Arima Haruzumi (有馬 晴純, 1483 – March 19, 1566) was a Japanese feudal lord in the Sengoku period.
[1] Initially known as Arima Sadazumi, he held the title of Shuri-dayu and a position in the shobanshu, the private guard of the Shogun.
His tenure as lord had the Arima at the height of their power, controlling trade in the strategically important Shimabara Peninsula, near modern-day Nagasaki.
In the course of his tenure as lord, Haruzumi clashed with many local daimyōs such as the Goto, Hirai, Matsuura, Omura, Saigo, and Taku.
In his later years, Portuguese vessels began to appear in the waters controlled by the Arima, and the family profited from foreign trade.