After Cromwell became Lord Protector in 1653 he began to formulate the so-called 'Western Design', a plan to attack and acquire Spanish territories in and around the Caribbean and to plant them with English settlers. In 1654 General Robert Venables and Admiral William Penn were given the task of turning this policy into reality.
The English invasion force of Jamaica landed on 10 May, 1655 without resistance and marched for Villa de la Vega, the capital. They found it almost empty and the Spanish, who had been weakened by smallpox, capitulated immediately. Some of the inhabitants fled to the north of the island and under Don Cristobal Arnaldo de Ysassi continued to harry the English until 1660, when they departed for Cuba. Jamaica was formally ceded to Britain by Spain under the Treaty of Madrid in 1670.