Satsuma invaded Ryukyu in the spring of 1609. When Satsuma landed in Northern Okinawa and attacked Nakijin Castle, the King's son and heir apparent, Shō Kokushi, was killed during the battle. Shō Nei surrendered on the fifth day of the fourth lunar month after Satsuma surrounded and breached Shuri Castle. Shō Nei was taken, along with a number of his officials, to Sunpu to meet with the retired "Shōgun" Tokugawa Ieyasu, then to Edo for a formal audience with "Shōgun" Tokugawa Hidetada, and then to Kagoshima, where he was forced to formally surrender and to declare a number of oaths to the Shimazu clan. At Edo, the "shōgun" stated that Shō Nei should be allowed to remain in power due to the long history of his line's rule over the islands.