sentences:  From 1600 onwards, counseled by the English gentleman of fortune, Sir Robert Sherley, he reorganized the army and strengthened it by increasing the number of "gholam" troops from 4,000 to 25,000.Allahverdi Khan led the Persian armies in a number of successful campaigns on both the eastern and the western frontiers of the Safavid empire, including the 1601-2 conquest of Bahrain.In 1605, during the Ottoman–Safavid War of 1603–1618, Allahverdi Khan besieged the Ottoman city of Van.