William II of Sicily
Accounts of his life and work are given in the funeral orations by Euthymius and Michael Choniates (of which manuscripts survive in the Bodleian Library in the University of Oxford). Niketas Choniates (viii.238, x.334) praised him as the most learned man of his age, a judgment which is difficult to dispute. He wrote commentaries on ancient Greek poets, theological treatises, addresses, letters, and an important account of the sack of Thessalonica by William II of Sicily in 1185.