Complex sentence: What is today the city of Fukuyama was founded as a castle town in 1619 by Mizuno Katsunari, a cousin of Tokugawa Ieyasu who was given command of a territory in western Japan consisting of southern Bingo Province and southwestern Bitchu Province.
Split into simpler sentences: What is today the city of Fukuyama was founded as a castle town in 1619 by Mizuno Katsunari, a cousin of shogun Tokugawa Ieyasu. Mizuno was given command of a territory in western Japan consisting of southern Bingo Province and southwestern Bitchu Province.