Antiochus III the Great (. 241 BC – 3 July 187 BC) was the sixth ruler of the Seleucid Empire, reigning from 223 BC to 187 BC. He ruled over the region of Syria and large parts of the rest of West Asia towards the end of the 3rd century BC. Rising to the throne at the age of eighteen in April/June 223 BC, his early campaigns against the Ptolemaic Kingdom were unsuccessful, but in the following years Antiochus gained several military victories and substantially expanded the empire's territory. His traditional designation, the Great, reflects an epithet he assumed. He also assumed the title Basileus Megas (Greek for 'Great King'), the traditional title of the Persian kings. A militarily active ruler, Antiochus restored much of the territory of the Seleucid Empire, before suffering a serious setback, towards the end of his reign, in his war against the Roman Republic. Declaring himself the "champion of Greek freedom against Roman domination", he waged a four-year war against Rome beginning in mainland Greece in the autumn of 192 BC[6][7] before being decisively defeated at the Battle of Magnesia. He died three years later on campaign in the east.