Shimazu clan
Throughout the Sengoku period, the Itō clan's most serious rival was the neighbouring Shimazu clan. The Shimazu clan had unified Satsuma Province and Ōsumi Province under its control, and began to clash with the Itō clan in 1570. The Itō clan was finally defeated by the Shimazu clan in 1578. After seeking help from then Shōgun Toyotomi Hideyoshi, the family's lands were restored in 1587 after his invasion of Kyūshū and subjugation of the Shimazu clan. By the Edo Era, the Itō clan regained its holdings, which came to be known as the Obi Domain. In the period after the Edo period, efforts were poured into quality education at the Shintoku Clan School in Obi. The school is where the Meiji period diplomat Marquis Komura Jutarō graduated from.