With the city now firmly in Portuguese hands, on December 1, 1510 Albuquerque resumed its administration and organizing its defence. The old castle was rebuilt in European fashion, under the supervision of architect Thomaz Fernandez, with 20 Portuguese stonemasons and many paid local labourers at his disposal. It was garrisoned with 400 Portuguese soldiers, while a corps of 80 mounted crossbowmen served as watchmen and gateguards of the city, commanded by the captain of Goa Rodrigo Rabelo, who received a bodyguard of 20 halberdiers. Francisco Pantoja was nominated alcaide-mor  of the city. A riverguard was also created, with two tall ships, a galley, a galleot and two brigantines. Timoji regained his post as tanadar-mor but his lowly caste as well as his mistreatment of underlings caused tensions within the Hindu society, and so he was replaced with his rival Melrao, who had at his disposal 5,000 men to assist with the defence. With an effective defensive system in place, Diogo Mendes de Vasconcelos requested the governor's permission to proceed to Malacca, which Albuquerque refused. Vasconcelos then attempted mutiny and tried to sail without permission, for which he was arrested and his pilots hanged. Albuquerque personally assumed the command of the expedition and in February 1511 left Goa towards Malacca. For the duration of the following year, the city would come under siege by the reorganized forces of general Pulad Khan, who would occupy the island of Goa and construct a bridge and a fortress at Benastarim. Pulad Khan would be replaced with Rassul Khan but he was likewise unable to recapture the city. The return of Albuquerque the following year, in August 1512, with considerable reinforcements, saw the defeat of Rassul Khan, who finally agreed to sign a peace treaty, formally granting Goa to the Portuguese.
Question: What was Rassul Khan forced into doing?
Answer: sign a peace treaty