Bailey was born in 1789 in Great Wenham, Suffolk, the son of John Bailey, of Wakefield and his wife Susannah. His parents had moved from Normanton, near Wakefield in around 1780 by which time they had already had at least three children (Ann, Elizabeth and William). Crawshay was the youngest of a further five children to be born in Great Wenham (the others being Susan, Joseph, John, and Thomas). His mother, Susannah was the sister of Richard Crawshay, the Ironmaster based at Cyfarthfa Castle near Merthyr Tydfil where Crawshay Bailey came at the age of twelve to work for his rich uncle in 1801, joining his elder brother Joseph. In 1809 he was a witness to his rich uncle's will, in which he was bequeathed the sum of £1,000 (equivalent to £55,000 in today's terms 2007 ).
Early business career: the iron master
Crawshay Bailey's early career was overshadowed by that of his elder brother, Joseph, later Sir Joseph Bailey, 1st Baronet, who, on his uncle's death in 1810 inherited 25% of the Cyfarthfa Works where he had been the manager. Joseph Bailey sold his share in Cyfarthfa, and together with Matthew Wayne later of Gadlys, Aberdare, he bought Nantyglo Ironworks from the Blaenavon Iron Company. At some point, Crawshay joined his brother at Nant-y-glo and, upon Wayne's departure to Aberdare, he became a partner with his brother in 1820. They afterwards bought the Beaufort ironworks and several collieries in the vicinity.
Crawshay Bailey and the coal industry
In contrast to most of his fellow iron masters, Bailey recognised the potential for the future development of the coal industry in South Wales, and far-sightedly bought up large areas of coal-rich land, at their agricultural value too, in the Rhondda Valleys, at Mountain Ash and Aberaman and was prepared to sit on these assets for nearly nine years before developing them as some of the richest coal and iron ore deposits in the world.
In a similar manner he waited until the most auspicious time before applying for a Parliamentary Act to open and run a railway company. In 1845 he was instrumental in setting up the Aberdare Railway, along with Sir John Josiah Guest to capitalise on further assets in the form of sinking new collieries and building new blast furnaces.
Soon after the Aberdare Railway was built, the Aberaman Ironworks and a number of collieries associated with it were opened. Bailey remained the owner of the Aberaman Estate but despite the profitability of his colliery activities, the depression in the iron trade meant that the enterprise did not prove as successful as Bailey had hoped so he decided to sell the Aberaman estate and return to Monmouthshire. He disposed of the entire Aberaman estate including its collieries, ironworks, brickworks and private railway, to the Powell Duffryn Steam Coal Co. by indenture dated 2 February 1867 for the sum of £123,500.
He was anti trade union and opposed to his workers organising themselves along these lines.
He had already been appointed High Sheriff of Brecknockshire in 1837 and also held the same office in Monmouthshire in 1850. He was a Conservative Member of Parliament (MP) for Monmouth Boroughs from 1852 to 1868 and was elected in five successive parliamentary elections.
By 1867 he owned iron works, blast furnaces, coalmines, tramways, railways and brickworks. He retired in this year, selling off all his assets over the next three years. Before 1851 he had retired to Llanfoist near Abergavenny, where he lived in Llanfoist House. Llanfoist Primary School had a house named after him.
John Griffith, rector of Merthyr, said of Crawshay Bailey:
He was the last and among the first of our great Iron Kings. He helped to develop this country before an iron rail was ever laid down on it. To the very last moment of his life he gave the whole of his energies to increase its manufacture. From the moment he joined his uncle at Cyfarthfa, a boy of twelve, till he died the other day at Llanfoist House, an aged man of 84, he never left the iron country, nor lost sight once of its steam and smoke. No manors, or parks, or aldermanic honours, or castles, or sea side palaces, ever drew him away from the grime and the soot of the smoky "Welsh Hills."— 
Crawshay Bailey was the original subject of the song now usually corrupted to Cosher Bailey
Crawshay Bailey had an Engine
It was always needin' mendin'
And dependin' on its power
It could do four miles an hour
Did you ever saw
Did you ever saw
Did you ever saw
Such a funny thing before?
(and so on—many, many verses in different versions) 
- "Death of Mr Crawshay Bailey". Cardiff Times. 13 January 1872. Retrieved 2 September 2014.
- Price, W.W. "Crawshay Bailey". Welsh Biography Online. Retrieved 2 September 2014.
- "Aberaman". Our Past. Rhondda Cynon Taf Library Service. Retrieved 30 August 2014.
- Jones, Alan (Spring 2005). "The 'Squire of Maindiff'". Gwent Local History (98): 53–62. Retrieved 26 March 2018.
- "Death of Mr Crawshay Bailey". Monmouthshire Merlin. 12 January 1872. Retrieved 2 September 2014.
- Robert Graves: Goodbye to all that
- Hansard 1803–2005: contributions in Parliament by Crawshay Bailey
|Parliament of the United Kingdom|
| Member of Parliament for Monmouth Boroughs
Sir John Ramsden
John Lloyd Vaughan Watkins
| High Sheriff of Brecknockshire
James Duncan Thomson
John Arthur Edward Herbert
| High Sheriff of Monmouthshire