However, Pedro Cabral entered into a conflict with the local Arab merchant guilds, with the result that the Portuguese factory was overrun in a riot and up to 70 Portuguese were killed. Cabral blamed the Zamorin for the incident and bombarded the city. Thus war broke out between Portugal and Calicut. Vasco da Gama invoked his royal letter to take command of the 4th India Armada, scheduled to set out in 1502, with the explicit aim of taking revenge upon the Zamorin and force him to submit to Portuguese terms. The heavily armed fleet of fifteen ships and eight hundred men left Lisbon on 12 February 1502. It was followed in April by another squadron of five ships led by his cousin, Estêvão da Gama (the son of Aires da Gama), which caught up to them in the Indian Ocean. The 4th Armada was a veritable da Gama family affair. Two of his maternal uncles, Vicente Sodré and Brás Sodré, were pre-designated to command an Indian Ocean naval patrol, while brothers-in-law Álvaro de Ataíde (brother of Vasco's wife Catarina) and Lopo Mendes de Vasconcelos (betrothed to Teresa da Gama, Vasco's sister) captained ships in the main fleet. On the outgoing voyage, da Gama's fleet opened contact with the East African gold trading port of Sofala and reduced the sultanate of Kilwa to tribute, extracting a substantial sum of gold. Pilgrim ship incident On reaching India in October 1502, da Gama's fleet intercepted Mirim, a ship of Muslim pilgrims at Madayi travelling from Calicut to Mecca. Described in detail by eyewitness Thomé Lopes and chronicler Gaspar Correia, da Gama looted the ship with over 400 pilgrims on board including 50 women, locked in the passengers, the owner and an ambassador from Egypt and burned them to death. They offered their wealth, which "could ransom all the Christian slaves in the Kingdom of Fez and much more" but were not spared. Da Gama looked on through the porthole and saw the women bringing up their gold and jewels and holding up their babies to beg for mercy. The lives of twenty children were spared against a forced conversion to Christianity Calicut After stopping at Cannanore, Gama drove his fleet before Calicut, demanding redress for the treatment of Cabral. Having known of the fate of the pilgrims' ship, the Zamorin adopted a conciliatory attitude towards the Portuguese and expressed willingness to sign a