Yāqūt ibn-'Abdullah al-Rūmī al-Hamawī (1179–1229) (Arabic: ياقوت الحموي الرومي) was an Arab biographer and geographer of Greek origin, renowned for his encyclopedic writings on the Muslim world. "al-Rumi" ("from Rûm") refers to his Greek (Byzantine) descent; "al-Hamawi" is taken after his masters name and ibn-Abdullah is a reference to his father's name, Abdullah. The word yāqūt means ruby or hyacinth.
Born in Greece, Yāqūt became a slave of a trader named Askar ibn Abi Nasr al-Hamawi who lived in Baghdad, Iraq. His master taught him accounting and trading and sent him to trade on his behalf.
He traveled two or three times to Kish in the Persian Gulf. In 1194 he quarrelled with his master and had to support himself by copying; he took advantage of the opportunity of studying under the grammarian Al-‘Ukbarî. After five years he returned to his old master and again travelled for him to Kish; on his return he set up for himself as a bookseller and began to write.
Yāqūt was one of the last scholars who had access to the libraries east of the Caspian Sea before the Mongol invasion of Central Asia, and during the next ten years he travelled in Persia, Syria, and Egypt, and visited the peaceful scholarly city of ancient Merv in present-day Turkmenistan, where he spent two years in libraries, learning much of the knowledge he would later use in his works. He also traveled to Balkh, Mosul and Aleppo. About 1222 he settled in Mosul and worked on his geography, the first draft of which was ready in 1224. After a journey to Alexandria in 1227 he went to Aleppo, where he died in 1229.
In his large geography, the Mu'jam ul-Buldān (ed. F. Wüstenfeld, 6 vols., Leipzig, 1866-73), the places mentioned in the literature or the stories of the Arabs are given in alphabetical order, with the correct vocalization of the names, an indication whether they are Arabic or foreign and their locality. Their history is often sketched with a special account of their conquest by Muslims and the name of the governor at the time is recorded. Attention is also given to the monuments they contain and the celebrities who were born in them or had lived there. In this way a quantity of old literature, both prose and poetry, is preserved by Yāqūt.