 Aizu, now fighting alone, had its forces besieged at Tsuruga Castle, the seat of the Aizu domain, in October 6, 1868.This was the start of a month-long siege.A detached unit from the Byakkotai ("White Tiger Company") — young, predominantly teenage, samurai — are famous for having committed seppuku (a form of ritual suicide) on Mount Iimori, overlooking the castle.