Tokugawa Leyasu was one of Toyotomi Hideyoshi's vassals. As an ally, he built up a powerful domain on the Kanto plain. Leyasu emerged from the renewed warfare after Hideyoshi's death and concentrated on consolidating power at home, unlike Hideyoshi, who campaigned overseas. He was granted the title shogun in 1603 by the emperor. Under him, the remaining daimyos were reorganized. Most of the islands in central Honshu were controlled by the Tokugawa family. Over time, the estates of numerous vassal daimyos were reduced in size or broken up and absorbed by the Tokugawa family. Tokugawa's victory put a clear end to the civil wars and brought a resemblance of political unity to the islands of Japan.