Ammianus Marcellinus was the last major historian of antiquity to write in Latin, and his work is the best source extant from the fourth century CE. As a soldier and man of letters, he continued the tradition of ancient men of action who also wrote history, a tradition running from Thucydides in the fifth century BCE to Procopius in the sixth century CE. Ammianus' writings, though not without their stylistic and philological problems, remain one of the most important historical works of late antiquity.