Manuchar continued his predecessors' efforts to extend the Dadiani's influence over the kingdom of Imereti, Mingrelia's nominal suzerain.
He led his army, equipped with artillery, over the Likhi mountains into Imereti and forced its king Rostom, the Dadiani's nominee, into flight to Mingrelia.
Dadiani offered to reinstate Rostom on terms of vassalage and himself promised peace and submission to Simon.
[1][2] Manuchar responded with mobilization and, accompanied by Rostom and his loyalists, attacked Simon at Opshkviti, defeated him and captured his cannons.
According to the 18th-century historian Prince Vakhushti, Manuchar died in a hunting incident, while pursuing a herd of deer, in 1611.