a palisade and a wall of rammed earth, to be erected at the edge of the port. A treaty was signed between Kotte and Portugal, with terms including: Parakramabahu officially declared himself a vassal of the Portuguese king Manuel I, offered a tribute of 10 elephants, 20 ruby rings and 400 cinnamon bars, and in exchange Portugal would provide military support for Kotte. Siege of Colombo (1520) The construction of the fort sparked a riot in Colombo, instigated by Muslim merchants and Buddhist monks. The construction site was attacked by Sinhalese, armed with bows and a few cannons – originally offered by the Muslim merchants to Parakramabahu – but the mob was dispersed by the much more powerful bombardment of the Portuguese ships anchored in the harbour. Parakramabahu intervened to put an end to the dispute, supporting the Portuguese. Siege of Colombo (1521) Parakramabahu died of natural causes shortly thereafter, being succeeded by Vijayabahu VII, who was opposed to Portuguese presence. Relations worsened, with the local population refusing to sell supplies to the Portuguese. In 1520, the now-complete fortress was besieged by a large army led by Vijayabahu, equipped with several hundred firearms. After a six month siege, Portuguese reinforcements arrived by sea, which forced Vijayabahu to lift the siege. Partition of Kotte In 1521, the three sons of Vijayabahu rebelled and killed him. The sons (Bhuvanekabahu, Pararajasingha, and Mayadunne) divided Vijayabahu's kingdom among themselves in the 'Spoiling of Vijayabahu'. Mayadunne received the Kingdom of Sitawaka, Pararajasingha was given the Principality of Raigama (taking the name Raigama Bandara), and Bhuvanekabahu ruled over the remaining part of Kotte (as Bhuvanekabahu VII). This event began the Crisis of the Sixteenth Century. The rivalries between these three new realms gave the Portuguese an opportunity to expand their influence on the island, by becoming involved in its internal politics. The Portuguese initially focused on securing their fort in Colombo and the cinnamon trade that took place there. Bhuvanekabahu of Kotte renewed the alliance that had been agreed by Parakramabahu, so the Portuguese also helped to defend Kotte against attacks from Sitawaka. Portuguese influence over Kotte grew with the military aid they provided. Defense of Kotte against Sitawaka (1521-1588) The first invasion of Kotte by Mayadunne was repulsed by a Bhunvanekabahu, assisted by forces despatched by the Portuguese Viceroy of Goa. Another attempt at seizing Kotte in 1537 failed when Mayadunne's forces were defeated by