The Shimabara domain was ruled by the Christian Arima clan
in the late Muromachi period. After the
Tokugawa government banned Christianity
the daimyô Arima Naozumi was replaced by Matsukura Shigemasa.
Matsukura enforced the prohibition against the Christians and raised
taxes to pay for the new castle Shimabara-jô (1618-24). This
repression of the peasants was a major factor leading to the Shimabara