His "sankin-kōtai" system forced "daimyōs" to reside in Edo in alternating sequence, spending a certain amount of time in Edo, and a certain amount of time in their home provinces. It is often said that one of the key goals of this policy was to prevent the "daimyōs" from amassing too much wealth or power by separating them from their home provinces, and by forcing them to regularly devote a sizable sum to funding the immense travel expenses associated with the journey (along with a large entourage) to and from Edo. The system also involved the "daimyōs" wives and heirs remaining in Edo, disconnected from their lord and from their home province, serving essentially as hostages who might be harmed or killed if the "daimyōs" were to plot rebellion against the shogunate.