At the beginning of the 1650s, the Irish massively abandoned the Spanish armies in Europe in order to integrate themselves in those of the French and Portuguese rivals of the Catholic Monarchy. However, in the islands of the Caribbean this process ran in reverse. On them, the Irish left the French and English settlement in order to take refuge in the territories under Spanish rule. Irish migration towards the Spanish Monarchy in the mid seventeenth century was divergent at both sides of the Atlantic . In addition, the patterns of integration in the Spanish Caribbean gave a completely different result.  

In the island of Hispaniola , the settlement of other European nations in the vicinity was regarded as a serious menace to the defensive system of the Spanish monarchy and to the own survival of the Spanish hold of the island. However, the attraction exerted by the Spanish Monarchy over the Irish in the American context, and the possibility that these would integrate themselves in its military and social system, made the rejection of foreign settlers in Spanish territories a more complex question. Irish migration to Hispaniola was an element which could be considered disruptive and weakening. The Spanish authorities regarded with distrust the presence of a foreign community with military knowledge and capability at the very heart of its defensive system. However, this element was transformed in a source of recruitment, military leadership which served to strengthen the Spanish control over the insular territory and the maritime corridors.   

The proposed paper attempts to analyse these complex problems through the study of Irish migration towards the island of Hispaniola and the reason they found, and gave, to do so, as a way to understand the different outcomes between the different territories of the Spanish Monarchy. It will be argued that, precisely, it is the different interaction of several factors (political context, migration, military participation and processes of integration) which explains the different evolution of the Irish community on both sides of the Atlantic .