When his Fula family came from Senegal to claim him, Chief Amadu, who now regarded Russin as his son and heir, refused to give him up. When Alimamy Amadu died in 1845, the people of Mafonda chose Russin as their ruler. But Russin was a modest man and refused to be crowned officially for several years. From the outset of his rule, Alimamy Rassin made clear his hatred of war and all forms of violence. He set up a fund for the promotion of peace to be replenished from fines levied in the chiefs court. He mediated successfully in political disputes in the Sanda Tendaren , Touko Limha , Yoni and Bombali Temne countries, occasionally sending his sons on official peace missions. When the Mandinka army of Samori Toure reached Mafonda in 1885, after occupying many parts of northern Sierra Leone, the invaders were so impressed by Russin's wise rule that they chose to withdraw and leave Mafonda in peace.
The British administration in Freetown was equally impressed with Alimamy Russin's rule and offered him a large annual stipend to continue with his efforts to establish peace among the interior rulers. But Russin rejected the offer, arguing that it was unethical to accept payment for the promotion of peace. He ruled wisely for the benefit of his people and not for political favors from the British.
Alimamy Russin died in 1890, six years before the chiefs lost their independence to British rule.