Thomas, Elizabeth, ‘We have nothing more valuable in our treasury’ : royal marriage in England, 1154-1272, Thèse de doctorat soutenue en 2010, (dir. J. Hudson, University of St Andrews)
That kings throughout the entire Middle Ages used the marriages of themselves and their children to further their political agendas has never been in question. What this thesis examines is the significance these marriage alliances truly had to domestic and foreign politics in England from the accession of Henry II in 1154 until the death of his grandson Henry III in 1272. Chronicle and record sources shed valuable light upon the various aspects of royal marriage at this time: firstly, they show that the marriages of the royal family at this time were geographically diverse, ranging from Scotland and England to as far abroad as the Empire, Spain, and Sicily. Most of these marriages were based around one primary principle, that being control over Angevin land-holdings on the continent. Further examination of the ages at which children were married demonstrates a practicality to the policy, in that often at least the bride was young, certainly young enough to bear children and assimilate into whatever land she may travel to. Sons were also married to secure their future, either as heir to the throne or the husband of a wealthy heiress. Henry II and his sons were almost always closely involved in the negotiations for the marriages, and were often the initiators of marriage alliances, showing a strong interest in the promotion of marriage as a political tool. Dowries were often the centre of alliances, demonstrating how much the bride, or the alliance, was worth, in land, money, or a combination of the two. One of the most important aspects for consideration though, was the outcome of the alliances. Though a number were never confirmed, and most royal children had at least one broken proposal or betrothal before their marriage, many of the marriages made were indeed successful in terms of gaining from the alliance what had originally been desired.
[Source : http://hdl.handle.net/10023/2001]