Horse-trading and wife-swapping: politics, marriage, and selaidecht in twelfth-century Ireland

On the eve of the English invasion (1169), Ireland’s marriage practices were regarded as barbarous and scandalous by contemporary European ecclesiastics. But were they really so divergent, and if so, why does it matter? This article proposes to explain the rationales underlying marriage with special reference to the Banshenchas, a twelfth-century record of aristocratic women and their sons. Close attention is given to pairings in terms of their dynastic affiliation and social standing, and a complex picture emerges: alliance was just one of a variety of political motives – others include suzerainty and local ties – and such strategic thinking was by no means universal. The expectations each family might have from a marriage of their daughters or sons existed on a spectrum from the very great to the very meagre; a spectrum greatly extended by the fact than an Irish royal dynasty might have many more children than their counterparts elsewhere in Europe. There are indications of female agency and even marriages of no political importance, as well as evidence to support the view of serial monogyny over polygyny. Most importantly, marriage could be considered a recognition of royal status among groups that shared a common kingship. Constituting or avoiding such matches therefore had implications as dynasties sought to monopolise these kingships. In one province in particular, the failure of any one group to edge out their rivals contributed to political crisis: this was Leinster, whose king, Díarmait Mac Murchada, asked Henry II’s aid in 1166 and thus enabled the English invasion.