In late 1654, English leader Oliver Cromwell launched the Western Design armada against Spain's colonies in the Caribbean. In April 1655, General Robert Venables led the armada in an attack on Spain's fort at Santo Domingo, Hispaniola. After the Spanish repelled this poorly executed attack, the English force then sailed for Jamaica, the only Spanish West Indies island that did not have new defensive works. In May 1655, around 7,000 English soldiers landed near Jamaica's capital, named Spanish Town and soon overwhelmed the small number of Spanish troops (at the time, Jamaica's entire population only numbered around 2,500).
extracted from:https://en.wikipedia.org/wiki/History_of_Jamaica#:~:text=Pre%2DColumbian%20Jamaica,-Main%20article%3A%20Pre&text=The%20first%20inhabitants%20of%20Jamaica,red%20pottery%20they%20left%20behind.