|↑ Bronze Age|
Ancient Near East (1200 BC – 500 BC)
India (1200 BC – 200 BC)
Europe (1200 BC – 1 BC)
China (600 BC – 200 BC)
Japan (100 BC – 300 AD)
Korea (400 BC – 400 AD)
Sub-Saharan Africa (1000 BC – 800 AD)
|↓ Ancient history|
The Iron Age is the period generally occurring after the Bronze Age, marked by the prevalent use of iron. Iron production is known to have taken place in Anatolia at least as early as 1200 BC, with some contemporary archaeological evidence pointing to earlier dates.
The early period of the age is characterized by the widespread use of iron or steel. The adoption of these materials coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles. The Iron Age as an archaeological term indicates the condition as to civilization and culture of a people using iron as the material for their cutting tools and weapons. The Iron Age is the third principal period of the three-age system created by Christian Thomsen (1788–1865) for classifying ancient societies and prehistoric stages of progress.
In historical archaeology, the ancient literature of the Iron Age includes the earliest texts preserved in manuscript tradition. Sanskrit and Chinese literature flourished in the Iron Age. Other texts include the Avestan Gathas, the Indian Vedas and the oldest parts of the Hebrew Bible. The principal feature that distinguishes the Iron Age from the preceding ages is the introduction of alphabetic characters, and the consequent development of written language which enabled literature and historic record.
The beginning of the Iron Age in Europe and adjacent areas is characterized by certain forms of implements, weapons, personal ornaments, and pottery, and also by systems of decorative design, which are altogether different from those of the preceding age of bronze. Metalsmithing expanded from the primary form in the Bronze Age, casting, to include forging. The system of decoration, which in the Bronze Age consisted chiefly of a repetition of rectilinear patterns, gave way to a system of curvilinear and flowing designs. The term "Iron Age" has low chronological value, because it did not begin simultaneously across the entire world. The dates and context vary depending on the region, and the sequence of ages is not necessarily true for every part of the earth's surface. There are areas, such as the islands of the South Pacific, the interior of Africa, and parts of North and South America, where peoples have passed directly from the use of stone to the use of iron without an intervening age of bronze.
- 1 Chronology
- 2 History
- 2.1 Near East
- 2.2 Europe
- 2.3 Asia
- 2.4 Africa
- 3 Gallery
- 4 See also
- 5 Further reading
- 6 References
- 7 External links
Around 3000 BC, iron was a scarce and precious metal in the Near East.[clarification needed] The earliest known iron artifacts are nine small beads, dated to 3200 BC, from burials in Gerzeh, northern Egypt, that were made from meteoric iron, and shaped by careful hammering. Iron's qualities, in contrast to those of bronze, were not understood. Between 1200 BC and 1000 BC, diffusion in the understanding of iron metallurgy and use of iron objects was fast and far-flung. In the history of ferrous metallurgy, iron smelting — the extraction of usable metal from oxidized iron ores — is more difficult than tin and copper smelting. These other metals and their alloys can be cold-worked, or melted in simple pottery kilns and cast in molds; but smelted iron requires hot-working and can be melted only in specially designed furnaces. It is therefore not surprising that humans only mastered iron smelting after several millennia of bronze metallurgy.
In 2005, metallurgical analysis by Hideo Akanuma of iron fragments found at Kaman-Kalehöyük in 1994 and dating to c. 1800 BC revealed that some of these fragments were in fact composed of carbon steel; these currently form the world's earliest known evidence for steel manufacture.
Modern archaeological evidence identifies the start of iron production as taking place in Anatolia around 1200 BC, though some contemporary archaeological evidence points to earlier dates.
Lack of archaeological evidence of iron production made it seem unlikely that it had begun earlier elsewhere, and the Iron Age was seen as a case of simple diffusion of a new and superior technology from an invention point in the Near East to other regions. It is now known that meteoric iron, or iron-nickel alloy, was used by various ancient peoples thousands of years before the Iron Age. Such iron, being in its native metallic state, required no smelting of ores. By the Middle Bronze Age, increasing numbers of smelted iron objects (distinguishable from meteoric iron by the lack of nickel in the product) appeared in the Middle East, Southeast Asia, and South Asia.
Pure iron is softer than bronze, and therefore produces tools which wear out faster. The advantage of using iron over bronze lay in cheaper production and the wide availability of iron ore. The systematic production and use of iron implements in Anatolia began around 2000 BC. Recent archaeological research in the Ganges Valley, India showed early iron working by 1800 BC. However, this metal was expensive, perhaps because of the complications of steel-making.
Anthony Snodgrass suggests that a shortage of tin, as a part of the Bronze Age Collapse and trade disruptions in the Mediterranean around 1300 BC, forced metalworkers to seek an alternative to bronze. As evidence, many bronze implements were recycled into weapons during this time. More widespread use of iron led to improved steel-making technology at lower cost. Thus, even when tin became available again, iron was cheaper, stronger, and lighter, and forged iron implements superseded cast bronze tools permanently.
Recent archaeological work has modified not only the above chronology, but also the causes of the transition from bronze to iron. New dates from India suggest that iron was being worked there as early as 1800 BC, and African sites are turning up dates as early as 1200 BC, confounding the idea that there was a simple discovery and diffusion model. Increasingly, the Iron Age in Europe is being seen as a part of the Bronze Age collapse in the ancient Near East, in ancient India (with the post-Rigvedic Vedic civilization), ancient Iran, and ancient Greece (with the Greek Dark Ages). In other regions of Europe, the Iron Age began in the 8th century BC in Central Europe and the 6th century BC in Northern Europe. The Near Eastern Iron Age is divided into two subsections, Iron I and Iron II. Iron I (1200–1000 BC) illustrates both continuity and discontinuity with the previous Late Bronze Age. There is no definitive cultural break between the 13th and 12th century BC throughout the entire region, although certain new features in the hill country, Transjordan, and coastal region may suggest the appearance of the Aramaean and Sea People groups. There is evidence, however, that shows strong continuity with Bronze Age culture, although as one moves later into Iron I the culture begins to diverge more significantly from that of the late 2nd millennium.
During the Iron Age, the best tools and weapons were made from steel, particularly alloys which were produced with a carbon content between approximately 0.30% and 1.2% by weight. Alloys with less carbon than this, such as wrought iron, cannot be heat treated to a significant degree and will consequently be of low hardness, while a higher carbon content creates an extremely hard but brittle material that cannot be annealed, tempered, or otherwise softened. Steel weapons and tools were nearly the same weight as those of bronze, but stronger. However, steel was difficult to produce with the methods available, and alloys that were easier to make, such as wrought iron, were more common in lower-priced goods. Many techniques have been used to create steel; Mediterranean ones differ dramatically from African ones, for example. Sometimes the final product is all steel, sometimes techniques like case hardening or forge welding were used to make cutting edges stronger.
Southwest Asia / Middle East
In the Mesopotamian states of Sumer, Akkad and Assyria, the initial use of iron reaches far back, to perhaps 3000 BC. One of the earliest smelted iron artifacts known was a dagger with an iron blade found in a Hattic tomb in Anatolia, dating from 2500 BC. The widespread use of iron weapons which replaced bronze weapons rapidly disseminated throughout the Near East (North Africa, southwest Asia) by the beginning of the 1st millennium BC.
Near East timeline
Ancient Near East
The Iron Age in the Ancient Near East is believed to have begun with the discovery of iron smelting and smithing techniques in Anatolia or the Caucasus and Balkans in the late 2nd millennium BC (c. 1300 BC). However, this theory has been challenged by the emergence of those placing the transition in price and availability issues rather than the development of technology on its own. The earliest bloomery smelting of iron is found at Tell Hammeh, Jordan around 930 BC (C14 dating).
The development of iron smelting was once attributed to the Hittites of Anatolia during the Late Bronze Age. It was believed that they maintained a monopoly on ironworking, and that their empire had been based on that advantage. Accordingly, the invading Sea Peoples were responsible for spreading the knowledge through that region. This theory is no longer held in the common current thought of the majority of scholarship, since there is no archaeological evidence of the alleged Hittite monopoly. While there are some iron objects from Bronze Age Anatolia, the number is comparable to iron objects found in Egypt and other places of the same time period; and only a small number of these objects are weapons. As part of the Late Bronze Age-Early Iron Age, the Bronze Age collapse saw the slow, comparatively continuous spread of iron-working technology in the region. The Ugaritic script was in use during this time, around 1300 BC. Ugarit was one of the centres of the literate world.
Assyro-Babylonian literature, written in the Akkadian language, of Mesopotamia (Assyria and Babylonia) continues into the Iron Age up until the 6th centuries BC. The oldest Phoenician alphabet inscription is the Ahiram epitaph, engraved on the sarcophagus of King Ahiram from circa 1200 BC. It has become conventional to refer to the alphabetic script as "Proto-Canaanite" until the mid-11th century BC, when it is first attested on inscribed bronze arrowheads, and as "Phoenician" only after 1050 BC. The Paleo-Hebrew alphabet is identical to the Phoenician alphabet and dates to the 10th century BC.
In Europe, the use of iron covers the last years of the prehistoric period and the early years of the historic period. The regional Iron Age may be defined as including the last stages of the prehistoric period and the first of the proto-historic periods. Iron working was introduced to Europe in the late 11th century BC, probably from the Caucasus, and slowly spread northwards and westwards over the succeeding 500 years. The widespread use of the technology of iron was implemented in Europe simultaneously with Asia.
Archaeological artifact from the work developed in the area of Citânia de Briteiros
The Iron Age in Europe is characterized by an elaboration of designs in weapons, implements, and utensils. These are no longer cast but hammered into shape, and decoration is elaborate curvilinear rather than simple rectilinear; the forms and character of the ornamentation of the northern European weapons resembles in some respects Roman arms, while in other respects they are peculiar and evidently representative of northern art. The dead were buried in an extended position, whereas in the preceding Bronze Age cremation had been the rule.
The Iron Age in Central Asia began when iron objects appear among the Indo-European Saka in present-day Xinjiang between the 10th century BC and the 7th century BC, such as those found at the cemetery site of Chawuhukou.
Archaeology in Thailand at sites Ban Don Ta Phet and Khao Sam Kaeo yielding metallic, stone, and glass artifacts stylistically associated with the Indian subcontinent suggest Indianization of Southeast Asia beginning in the fourth to second centuries BC during the late Iron Age.
South Asia timeline
The history of metallurgy in the Indian subcontinent began during the 2nd millennium BC. Archaeological sites in India, such as Malhar, Dadupur, Raja Nala Ka Tila and Lahuradewa in present day Uttar Pradesh show iron implements in the period 1800 BC – 1200 BC. Archaeological excavations in Hyderabad show an Iron Age burial site. Rakesh Tewari believes that around the beginning of the Indian Iron Age (13th century BC), iron smelting was widely practiced in India. Such use suggests that the date of the technology's inception may be around the 16th century BC.
Epic India is traditionally placed around early 10th century BC and later on from the Sanskrit epics of Sanskrit literature. Composed between approximately 1500 BC and 600 BC of pre-classical Sanskrit, the Vedic literature forms four Vedas (the Rig, Yajur, Sāma and Atharva). The main period of Vedic literary activity is the 9th to 7th centuries when the various schools of thought compiled and memorized their respective corpora. Following this, the scholarship around 500 to 100 BC organized knowledge into Sutra treatises.
The beginning of the 1st millennium BC saw extensive developments in iron metallurgy in India. Technological advancement and mastery of iron metallurgy was achieved during this period of peaceful settlements. One iron working centre in east India has been dated to the first millennium BC. In Southern India (present day Mysore) iron appeared as early as 12th to 11th centuries BC; these developments were too early for any significant close contact with the northwest of the country. The Indian Upanishads mention metallurgy. and the Indian Mauryan period saw advances in metallurgy. As early as 300 BC, certainly by 200 AD, high quality steel was produced in southern India, by what would later be called the crucible technique. In this system, high-purity wrought iron, charcoal, and glass were mixed in crucible and heated until the iron melted and absorbed the carbon.
The protohistoric Early Iron Age in Sri Lanka lasted from 1000 to 600 BC. Radiocarbon evidence has been collected from Anuradhapura and Aligala shelter in Sigiriya. The Anuradhapura settlement is recorded to extend 10 hectares by 800 BC and grew to 50 hectares by 700 - 600 BC to become a town. The skeletal remains of an Early Iron Age chief were excavated in Anaikoddai, Jaffna. The name 'Ko Veta' is engraved in Brahmi script on a seal buried with the skeleton and is assigned by the excavators to the 3rd century BC. Ko, meaning "King" in Tamil, is comparable to such names as Ko Atan and Ko Putivira occurring in contemporary Brahmi inscriptions in south India. It is also speculated that Early Iron Age sites may exist in Kandarodai, Matota, Pilapitiya and Tissamaharama.
East Asia timeline
In China, Chinese bronze inscriptions are found around 1200 BC. The development of iron metallurgy was transpired by the 9th century BC. The large seal script is identified with a group of characters from a book entitled Shĭ Zhoù Piān (ca. 800 BC). Iron metallurgy reached the Yangzi Valley toward the end of the 6th century BC. The few objects were found at Changsha and Nanjing. The mortuary evidence suggests that the initial use of iron in Lingnan belongs to the mid-to-late Warring States period (from about 350 BC). Important non-precious husi style metal finds include Iron tools found at the Tomb at Ku-wei ts'un of the fourth century BC.
The techniques used in Lingnan are a combination of bivalve moulds of distinct southern tradition and the incorporation of piece mould technology from the Zhongyuan. The products of the combination of these two periods are bells, vessels, weapons and ornaments and the sophisticated cast.
Iron objects were introduced to the Korean peninsula through trade with chiefdoms and state-level societies in the Yellow Sea area in the 4th century BC, just at the end of the Warring States Period but before the Western Han Dynasty began. Yoon proposes that iron was first introduced to chiefdoms located along North Korean river valleys that flow into the Yellow Sea such as the Cheongcheon and Taedong Rivers. Iron production quickly followed in the 2nd century BC, and iron implements came to be used by farmers by the 1st century in southern Korea. The earliest known cast-iron axes in southern Korea are found in the Geum River basin. The time that iron production begins is the same time that complex chiefdoms of Proto-historic Korea emerged. The complex chiefdoms were the precursors of early states such as Silla, Baekje, Goguryeo, and Gaya Iron ingots were an important mortuary item and indicated the wealth or prestige of the deceased in this period.
Iron items, such as tools, weapons, and decorative objects, are postulated to have entered Japan during the late Yayoi period (c. 300 BC to 300 AD) or the succeeding Kofun period (c. 250 AD to 538 AD), most likely through contacts with the Korean Peninsula and China.
Distinguishing characteristics of the Yayoi period include the appearance of new pottery styles and the start of intensive rice agriculture in paddy fields. Yayoi culture flourished in a geographic area from southern Kyūshū to northern Honshū. The Kofun and the subsequent Asuka periods are sometimes referred to collectively as the Yamato period; The word kofun is Japanese for the type of burial mounds dating from that era.
In Africa, where there was no continent-wide universal Bronze Age, the use of iron succeeded immediately the use of stone. Metallurgy was characterized by the absence of a Bronze Age, and the transition from "stone to steel" in tool substances. Sub-Saharan Africa has produced very early instances of carbon steel found to be in production around 2000 years ago in northwest Tanzania, based on complex preheating principles. Nubia was one of the relatively few places in Africa to have a sustained Bronze Age along with Egypt and much of the rest of North Africa. The Meroitic script was developed in the Napatan Period (c. 700–300 BC).
In the Black Pyramid of Abusir, dating before 2000 BC, Gaston Maspero found some pieces of iron. In the funeral text of Pepi I, the metal is mentioned. A sword bearing the name of pharaoh Merneptah as well as a battle axe with an iron blade and gold-decorated bronze shaft were both found in the excavation of Ugarit.
Iron metal is singularly scarce in collections of Egyptian antiquities. Bronze remained the primary material there until the conquest by Assyria. The explanation of this would seem to lie in the fact that the relics are in most cases the paraphernalia of tombs, the funeral vessels and vases, and iron being considered an impure metal by the ancient Egyptians it was never used in their manufacture of these or for any religious purposes. It was attributed to Seth, the spirit of evil who according to Egyptian tradition governed the central deserts of Africa.
Very early copper and bronze working sites in Niger, West Africa may date to as early as 1500 BC. There is also evidence of iron metallurgy in Termit, Niger from around this period. In Central Africa, iron working may have been practiced as early as the 3rd millennium BC. It was once believed that iron and copper working in Sub-Saharan Africa spread in conjunction with the Bantu expansion, from the Cameroon region to the African Great Lakes in the 3rd century BC, reaching the Cape around 400 AD.
Sub-Saharan Africa has produced very early instances of carbon steel found to be in production around 2,000 years ago in northwest Tanzania, based on complex preheating principles. These discoveries, according to Schmidt and Avery (archaeologists credited with the discovery) are significant for the history of metallurgy.
|Iron Age Examples|
- List of archaeological periods, List of archaeological sites
- Blast furnace, Roman metallurgy
- Synoptic table of the principal old world prehistoric cultures
- Waldbaum, Jane C. From Bronze to Iron. Göteburg: Paul Astöms Förlag (1978): 56-8
- The Junior Encyclopædia Britannica: A reference library of general knowledge. (1897). Chicago: E.G. Melvin.
- C. J. Thomsen and Jens Jacob Asmussen Worsaae first applied the system to artifacts.
- Chisholm, H. (1910). The Encyclopædia Britannica. New York: The Encyclopædia Britannica Co.
- Rehren T, et al, "5,000 years old Egyptian iron beads made from hammered meteoritic iron", Journal of Archaeological Science 2013 text
- Akanuma, H. (2005). "The significance of the composition of excavated iron fragments taken from Stratum III at the site of Kaman-Kalehöyük, Turkey". Anatolian Archaeological Studies 14: 147–158.
- "Ironware piece unearthed from Turkey found to be oldest steel". The Hindu (Chennai, India). 2009-03-26. Retrieved 2009-03-27.
- Archaeomineralogy, p. 164, George Robert Rapp, Springer, 2002
- Understanding materials science, p. 125, Rolf E. Hummel, Springer, 2004
- Ironware piece unearthed from Turkey found to be oldest steel in The Hindu, Thursday, March 26, 2009
- The origins of Iron Working in India: New evidence from the Central Ganga plain and the Eastern Vindhyas by Rakesh Tewari (Director, U.P. State Archaeological Department)
- A.M.Snodgrass (1966), "Arms and Armour of the Greeks". (Thames & Hudson, London)
- A. M. Snodgrass (1971), "The Dark Age of Greece" (Edinburgh University Press, Edinburgh).
- Theodore Wertime and J. D. Muhly, eds. The Coming of the Age of Iron (New Haven, 1979).
- Duncan E. Miller and N.J. Van Der Merwe, 'Early Metal Working in Sub Saharan Africa' Journal of African History 35 (1994) 1–36; Minze Stuiver and N.J. Van Der Merwe, 'Radiocarbon Chronology of the Iron Age in Sub-Saharan Africa' Current Anthropology 1968.
- How Old is the Iron Age in Sub-Saharan Africa? — by Roderick J. McIntosh, Archaeological Institute of America (1999)
- Iron in Sub-Saharan Africa — by Stanley B. Alpern (2005)
- Richard Cowen () The Age of Iron Chapter 5 in a series of essays on Geology, History, and People prepares for a course of the University of California at Davis. Online version.
- Alex Webb, "Metalworking in Ancient Greece"
- Jane C. Waldbaum, From Bronze to Iron: The Transition from the Bronze Age to the Iron Age in the Eastern Mediterranean (Studies in Mediterranean Archaeology, vol. LIV, 1978).
- Muhly, James D. 'Metalworking/Mining in the Levant' pp. 174-183 in Near Eastern Archaeology ed. Suzanne Richard (2003), pp. 179-180.
- Waldbaum, Jane C. From Bronze to Iron. Göteburg: Paul Astöms Förlag (1978): 56-8.
- Coulmas, Florian, Writing Systems of the World, Blackwell Publishers Ltd, Oxford, 1989. p. 141.
- Markoe, Glenn E., Phoenicians. University of California Press. p. 111 ISBN 0-520-22613-5
- Riederer, Josef; Wartke, Ralf-B.: "Iron", Cancik, Hubert; Schneider, Helmuth (eds.): Brill's New Pauly, Brill 2009
- John Collis, "The European Iron Age" (1989)
- Mark E. Hall, "Towards an absolute chronology for the Iron Age of Inner Asia," Antiquity 71.274 , 863-74.
- Glover, I.C.; Bellina, B. "Ban Don Ta Phet and Khao Sam Kaeo: The Earliest Indian Contacts Re-assessed". Early Interactions Between South and Southeast Asia: Reflections on Cross-cultural Exchange 2 (17): 17–45.
- "News By Industry". The Times Of India. 2008-09-10.
- Director of Archaeology, (Uttar Pradesh)
- Early Antiquity By I. M. Drakonoff. Published 1991. University of Chicago Press. ISBN 0-226-14465-8. pg 372
- Upanisads By Patrick Olivelle. Published 1998. Oxford University Press. ISBN 0-19-283576-9. pg xxix
- The New Cambridge History of India By J. F. Richards, Gordon Johnson, Christopher Alan Bayly. Published 2005. Cambridge University Press. ISBN 0-521-36424-8. pg 64
- Juleff, G. (1996), "An ancient wind powered iron smelting technology in Sri Lanka", Nature, 379 (3): 60–63.
- Lahiru Weligamage (2002) The Ancient Sri Lanka
- Deraniyagala, Siran, The Prehistory of Sri Lanka; an ecological perspective. (revised ed.), Colombo: Archaeological Survey Department of Sri Lanka, 1992: 709-29
- Karunaratne and Adikari 1994, Excavations at Aligala prehistoric site. In: Bandaranayake and Mogren (1994). Further studies in the settlement archaeology of the Sigiriya-Dambulla region. Sri Lanka, University of Kelaniya: Postgraduate Institute of Archaeolog :58
- Mogren 1994. Objectives, methods, constraints and perspectives. In: Bandaranayake and Mogren (1994) Further studies in the settlement archaeology of the Sigiriya-Dambulla region. Sri Lanka, University of Kelaniya: Postgraduate Institute of Archaeolog: 39.
- F. R. Allchin 1989. City and State Formation in Early Historic South Asia. South Asian Studies 5:1-16: 3
- Indrapala, K. The Evolution of an ethnic identity: The Tamils of Sri Lanka, pp. 324
- Deraniyagala, Siran, The Prehistory of Sri Lanka; an ecological perspective. (revised ed.), Colombo: Archaeological Survey Department of Sri Lanka, 1992: 730-2, 735
- Derevianki, A. P. 1973. Rannyi zheleznyi vek Priamuria
- David N. Keightley. The Origins of Chinese Civilization. Page 226.
- Higham, Charles. 1996. The Bronze Age of Southeast Asia
- Encyclopedia of World Art: Landscape in art to Micronesian cultures. McGraw-Hill. 1964.
- Kim, Do-heon. 2002. Samhan Sigi Jujocheolbu-eui Yutong Yangsang-e Daehan Geomto [A Study of the Distribution Patterns of Cast Iron Axes in the Samhan Period]. Yongnam Kogohak [Yongnam Archaeological Review] 31:1–29.
- Taylor, Sarah. 1989. The Introduction and Development of Iron Production in Korea. World Archaeology 20(3):422–431.
- Yoon, Dong-suk. 1989. Early Iron Metallurgy in Korea. Archaeological Review from Cambridge 8(1):92–99.
- Barnes, Gina L. 2001. State Formation in Korea: Historical and Archaeological Perspectives. Curzon, London.
- Lee, Sung-joo. 1998. Silla – Gaya Sahoe-eui Giwon-gwa Seongjang [The Rise and Growth of Silla and Gaya Society]. Hakyeon Munhwasa, Seoul.
- Prehistoric Archaeological Periods in Japan, Charles T. Keally
- Richard Cowen, 'The Age of Iron Chapter 5 in a series of essays on Geology, History, and People prepares for a course of the University of California at Davis. Online version
- Iron in Africa: Revising the History, UNESCO Aux origines de la métallurgie du fer en Afrique, Une ancienneté méconnue: Afrique de l'Ouest et Afrique centrale.
- Heather Pringle, Seeking Africa's first Iron Men. Science 323:200-202. 2009.
- Peter Schmidt, Donald H. Avery. Complex Iron Smelting and Prehistoric Culture in Tanzania, Science 22 September 1978: Vol. 201. no. 4361, pp. 1085 - 1089
- Collins, Rober O. and Burns, James M. The History of Sub-Saharan Africa. New York:Cambridge University Press, p. 37. ISBN 978-0-521-68708-9.
- A site with a focus on Iron Age Britain from resourcesforhistory.com
- Andre Gunder Frank and William R. Thompson, Early Iron Age economic expansion and contraction revisited. American Institute of Archaeology, San Francisco, Ca., January, 2004.
- Mass burial suggests massacre at Iron Age hill fort. Archaeologists have found evidence of a massacre linked to Iron Age warfare at a hill fort in Derbyshire. BBC. 17 April 2011