Men, Women, Marriage and Power in the Earldom and Duchy of Lancaster, 1265-1399
The story of the people in the family of the Earls and Dukes of Lancaster in the period of the Hundred Years War provides many indications as to what the diplomatic policies and practices of the English were at any given time. In her PhD thesis, Rebecca Holdorph studies this in-depth. The research and analysis, available in pdf format via the University of Southampton, is a wonderful academic study of the complex nature of marriage contracts.
For contrast with an earlier period and different European setting, see Medieval Women, Material Culture, and Power: Matilda Plantagenet and her Sisters by Jitske Jasperse.
Holdorph’s study is particularly useful in relation to the Hundred Years War. It explores John of Gaunt’s marriage to Constance of Castile. This marriage led to Gaunt having a claim, by right of his wife, to the Castillian throne. It followed involvement of forces from Aquitaine under the Black Prince in the Castillian Civil Wars. Furthermore, it illustrates the way in which diplomacy, warfare and marriage contracts are interrelated at the time.
Image: Detail from Froissart’s Chronicles, depicting Constance at the surrender of Santiago de Compostela to her husband