Mark with Japanese Mark: 仙台住　清定 "Sendai ju | #457992

仙台住　清定 "Sendai ju Kiyosada". This mark is from a tsuba and was made by Kiyosada, who worked as a sword engraver (soukenkinkou) in Mutsu Province (present-day Fukushima Prefecture). Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons. A tsuba is a sword guard designed to protect the hand from contact with the blade. It also balances the weight of the sword.