Yoshiaki was a son of Omura Sumitada. He commanded troops in the 1st Korean Campaign and elected to remain neutral during the Sekigahara campaign. As a result he was ordered to retire in favor of his son Suminobu. Like his father he was a Christian and was known in this as Dom Sancho.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005