 Complete the following phrase:  In 447, Attila invaded the Balkans and Thrace. The war came to an end in 449 with an agreement in which the Romans agreed to pay Attila an annual tribute of 2100 pounds of gold. Throughout their raids on the Eastern Roman Empire, the Huns had maintained good relations with the Western Empire. However, Honoria, sister of the Western Roman Emperor Valentinian III, sent Attila a ring and requested his help to escape her betrothal to a senator. Attila claimed her as his bride and half the Western Roman Empire as dowry. Additionally, a dispute arose about the rightful heir to a king of the Salian Franks. In 451, Attilas forces entered Gaul. Once in Gaul, the Huns first attacked Metz, then their armies continued westward, passing both Paris and Troyes to lay siege to Orléans. Flavius Aetius was given the duty of relieving Orléans by Emperor Valentinian III. A combined army of Roman and Visigoths then defeated the Huns at the 