Sultan Firuz Shah Tughluq started the second invasion of Bengal in 1359. The Tughlaqs declared Zafar Khan Fars, a Persian noble and son-in-law of Fakhruddin Mubarak Shah, as the legitimate ruler of Bengal. Firuz Shah Tughluq led an army consisting of 80,000 cavalry, a large infantry and 470 elephants to Bengal. Sikandar Shah took refuge in the fortress of Ekdala, in the same way his father did earlier. The Delhi forces besieged the fort. The Bengal army strongly defended their stronghold until the start of the monsoon. Eventually, Sikandar Shah and Firuz Shah reached a peace treaty, in which Delhi recognized Bengal's independence and withdrew its armed forces.