I. Emperor of the West from A. D. 407 to 472. He was the son-in-law of the emperor Mercian, and was invested with the purple at the suggestion of Ricimer, who ultimately became his son-in-law. Anthemius and Ricimer soon quarrelled, however, and then the latter, proclaiming Olybrius emperor, laid siege to Rome. The city was taken by storm, and Anthemius was slain.

II. An architect and mathematician of Tralles in Lydia, who flourished in the 6th century. He designed for the emperor Justinian the plan and commenced the building of the church of St. Sophia. A fragment of one of his mathematical works was published at Paris in 1777.