 Complete the following phrase:  Mamia may have been the Georgian ruler who defeated the Burgundians at Batumi and imprisoned their leader, Geoffroy de Thoisy, in 1445. Thoisy was only released through the good services of the Trapezuntine emperor John IV Megas Komnenos. The Gurieli, whose lordship lay between the Trapezuntine theme of Lazia and Mingrelia, had close ties with the Komnenoi. David Komnenos sent his wife, Helena, to Mamia for safety just before the Ottoman military 