From my recollection of West Indian history many of the earliest settlers in Montserrat were Irish, but they were generally subsistence farmers and indentured servants on the sugar plantations occupying the lower rungs of the socio-economic ladder, just one step up from slavery, while the sugar plantations were generally owned or run by the English who were not very favourably inclined to their Irish labourers and neighbors. There was also intermarriage and co-mingling between the Africans and the Irish leading to a large mixed race mulatto population.
Montserrat, however, never became a typical English West Indian island, where African slaves vastly out numbered a handful of Whites and racial mixture hardly ever took place. In the eighteenth century, Montserrat had two oppressed races. The Penal Laws, intended to crush Catholic, Celtic Ireland, applied also to Montserrat. The Irish, already reduced to poverty, suffered political disenfranchisement and religious persecution. Many of the young men emigrated but enough remained to constitute a peasant class eking out a bare living on marginal land. It was perhaps natural that the Irish and Africans at the bottom of the social structure worked, drank and made love together. An Afro-Irish population came into existence, its growth disguised by the tendency of English officials to count people as "Negro" if they had the slightest trace of African ancestry. We can glimpse the hidden reality when we find slaves named Bridget or Tom Kerwin and increasing reference to free "mulattos." In the eighteenth century, the sugar boom ended and fresh imports of Africans ceased to arrive in Montserrat. The process of Afro-Irish mixing therefore accelerated and each generation was more racially mixed than the one-before.
http://users.ev1.net/~gpmoran/Monteserrat.htmAfter England's civil war and Oliver Cromwell's invasion and conquest of Ireland many of his Irish and Scottish prisoners got shipped off to the Caribbean islands to work as indentured servants on the sugar plantations. They had it pretty rough as they were often treated much the same as were the African slaves, and since they were not accustomed to the heat of the tropics it must have been quite a hellish existence for them, as it undoubtedly was for the Africans. In certain areas of Barbados until relatively recently descendents of these Irish/Scotch indentured servants could still be identified by their white skin and comparative poverty compared to the other white minority occupants of the island.
In Barbados, these poor-white descendents of these indentured servants were called "redlegs" (presumably from their ancestors sunburnt legs after working out in the sugar cane fields) as a term of derision by both the blacks and the better off whites.
After becoming friends with an Irishman, I got the impression that the murderous and inhumane treatment of the Irish by Oliver Cromwell's invading army 300 years ago is still a sore spot that they find hard to forget. It does help explain as well why there is still so much tension between the Catholics and the Protestants in Northern Ireland to this day.
Barbadosed
Africans and Irish in Barbados
During the 1600's, African slaves and Irish natives shared a common fate on the island of Barbados. Slaves first arrived on the island in the 1620's with the first white settlers and continued to be brought there as the need for labor created a new market for the international slave trade. By 1645, the black population on the island was 5680, and by 1667, there were over 40,000 slaves on the island. In the early years of the colony's growth, Barbados also became a destination for military prisoners and Irish natives. Oliver Cromwell "barbadosed" Irish who refused to clear off their land and allowed other Irish to be kidnaped from the streets of Ireland and transported to Barbados. Those who were barbadosed were sold as slaves or indentured servants, to British planters. They lived in slave conditions and had no control over the number of years they had to serve. The number of Barbadosed Irish in not known and estimates very widely, from a high of 60,000 to a low of 12,000.
http://www.yale.edu/glc/tangledroots/Barbadosed.htm