Between 1109 and 1328 – when the direct Capetian line was extinguished and women were unequivocally bared from the French throne – a total of sixteen royal women asserted claims or were acclaimed to the thrones of Aragon, Castile and León, England, France, Jerusalem, Navarre, Scotland, and Sicily, with varying degrees of success. In chronological order, they were: Urraca of León-Castile (d. 1126), Melisende of Jerusalem (d. 1161), Empress Matilda (d. 1167), Petronila of Aragon (d. 1173), Sibylla of Jerusalem (d. 1190), Isabella I of Jerusalem (d. 1205), Constance I of Sicily (d. 1198), Maria of Montferrat (d. 1212), Isabella II of Jerusalem (d. 1228), Berenguela of Castile (d. 1246), Sancha (d. 1243) and Dulce (d. 1248) of León, Constance II of Sicily (d. 1305), Juana I of Navarre (d. 1305), Margaret of Norway (d. 1290), and Juana II of Navarre (d. 1349). Notably, only three of these fifteen claims were unsuccessful: Matilda's claim to the English throne (1135–48), Sancha and Dulce of León's joint claim to the Leonese throne (1230), and Juana II of Navarre's claim to the French throne (1316 and 1328).

In the Middle Ages, dynastic contingency led to female succession within European hereditary monarchies. What is less evident is the how, why, and when female succession and female royal rulership were experienced. As rulers positively sanctioned by God, those heiresses who ascended royal thrones were allegedly the equivalent to a king. And yet, the reality of medieval attitudes towards female rule meant that women's power, in practice, was not quite on par with that of a king. My larger research project, of which this article represents a portion, examines the reality of female rule, by means of a systematic and comparative examination of the life experiences and political careers of the sixteen women who sought to claim the title of queen in their own right, rather than as the wife of a king. To do so, the project considers their position, perception, and actual power, how these claims to medieval royal thrones were handled, the circumstances within which these women succeeded and failed to achieve their claims, and the political traditions which played a role in these developments. The present article focuses on the position and perception of the first four women within my project to assert claims to royal thrones: Urraca of León-Castile, Melisende of Jerusalem, Empress Matilda, and Petronila of Aragon.