Nawabs of Bengal, Azimabad (Patna) Mint, Silver 1/2 Rupee, 5.73Grms, in the name of Alamgir II, RY 3, trident symbol as a mint markThis coin had been issued during the time of Bengal Nawab Siraj ud Daulah as the period of RY 3 of Alamgir II was from 05/1756(08/1169) to 04/1757(08/1170). And the reign period of last independent Bengal Nawab Siraj-ud-Daula was 04/1756(07/1169) to 23/06/1757(05/10/1170). So the RY/date combination comes under the ruling period of Nawab Siraj-ud-Daula.