 After centuries of warfare, the Silla Kingdom, with their Tang allies, managed to unify much of what is now North and South Korea under the dominion of a single government in a period historians usually refer to as Unified Silla.While Silla's Tang allies were useful in helping the Silla rulers destroy their rivals, the kingdoms of Baekje and Goguryeo, after their mutual enemies were defeated the allies found themselves at cross purposes.The Tang emperor, following the ambitions of his predecessors, wanted to incorporate Korea into his empire while the Silla rulers vowed to maintain an independent realm.