James Hamilton and Hugh Montgomery are sometimes called the founding fathers of the Ulster-Scots. In 1606 they commenced a private, self-financed settlement of County Antrim and County Down, in advance of the better-known 1610 'Plantation of Ulster'.
Now, more than 400 years later it is interesting to note that the majority of their direct descendents (those who still carry the Hamilton and Montgomery surnames, in any case) still remain true to the political aims of the plantation. In other words, the majority of Hamiltons and Montgomeries in Northern Ireland are unionists, and have not been assimilated into the 'native' population. Some of this lack of assimilation can probably be ascribed to the 'ethnic cleansing' of the settled areas, in which very few 'natives' remained for much of the period since the plantation. Even today large areas of north Down and south Antrim contain very few Catholics – the situation was, presumably, more extreme in the 17th, 18th and 19th centuries, so the Hamiltons and Montgomeries would have had less opportunity to intermarry with 'natives'. In more mixed areas the story may have been different, but that is another story.
The Ulster's Doomed database contains the names of 68 Hamiltons who have played a political role in the past generation or so. Of these, 53 are (or have been) associated with unionist parties or independent unionists. 11 have been associated with 'centrist' parties (Alliance, Green, Workers Party, Independents), and only 4 have been associated with nationalism.
Similarly, the database contains the political histories of 34 recent Montgomeries. These have also been largely associated with unionism (28), with only 4 being associated with either the SDLP or Sinn Féin, and only 2 with centrist groups.
So it seems that the patterns set down in the old plantations are continuing to the present day. Or are they? All of the nationalist Hamiltons and Montgomeries have all appeared on the political scene since the year 2000. Could it be that as Northern Ireland has become more urban, more modern and (hopefully) more liberal, mixed marriages are becoming more common, and some of the products of such mixed marriages are crossing political boundaries?
A similar exercise can, of course be carried out on any other surname found in Northern Ireland (and there are a lot). Such exercises are, of course, far from scientific, and the Ulster's Doomed database makes no claims to be complete or even 100% accurate – but as time goes on, more and more nationalists can be found with traditionally 'Protestant' surnames. For example, the very first nationalist Robinsons made their political debuts only in 2005.
The reverse is, of course, also true. There are unionists called O'Neill, Maginnis, Donnelly, Maguire and so on – though few if any of their families have been Catholic for many generations. The course of Northern Irish politics will be determined partly by the ability of each side to poach from the other's 'tribe'. Up to recently there was little intermarriage, even after hundreds of years of co-existence, but recently the two tribes have started to mix far more than before – a result of looser family ties, better education, desegregated workplaces and colleges. Little by little the walls between the 'planters' and the 'gaels' are coming down, and as they do so there will be more and more new voters with a foot in both camps. How they go on to vote will be of great importance and interest.
Assimilation is one of the greatest dangers to a 'planted' population, especially if they no longer live separated from the pre-existing population. For many years a large proportion of Northern Ireland's Protestants lived in areas that were, to all extents and purposes, mono-religious, and thus they maintained their numbers and their ethos. The same was not true in the south, and as a result southern Protestants are almost entirely assimilated into the wider society. As Northern Ireland's Catholic population expands and especially as it expands in traditionally Protestant east Ulster, the possibility that it will assimilate parts of the Protestant population grows stronger; here Protestantism's exclusivity acts against its better interests – its long-standing refusal to allow Catholics into its space (best demonstrated by the Orange Order), compared with Catholicism's far more open attitude towards its space (nationalism, culture, language, etc) means that assimilation into the 'catholic/nationalist' community is considerably easier than assimilation into the 'protestant/unionist' community.
The small numbers of nationalist Hamiltons and Montgomeries is – after a mere 400 years – unlikely to herald an imminent flood, but as the numbers in the two communities approach parity in the next ten years, every assimilation will count. It is important that the Irish nation keeps its doors open, and remembers that it is a nation of Catholics, Protestant, Dissenters, and increasingly atheists and non-Christians too. A warm house for all the children of Ireland is better for all of us.