• January 1, 1957 - Parts of
Yotsukaidō merged into the city of
Sakura. • September 1, 1964 - The village of
Shiroi gained town status. • April 1, 1981 - The town of Yotsukaidō gained city status. • April 1, 1985 - The village of
Tomisato gained town status. • April 1, 1992 - The town of
Yachimata gained city status. • April 1, 1996 - The town of
Inzai gained city status. • April 1, 2001 - The town of Shiroi gained city status. • April 1, 2002 - The town of Tomisato gained city status. • March 23, 2010 - The villages of
Inba and
Motono merged into the city of
Inzai. ==References==