The Date of the Union between John III Vatatzes and Constance of Hohenstaufen

Abstract The betrothal of a daughter of Frederick II, Constance, to John III Vatatzes, emperor of Nicaea, is one of the most significant events of thirteenth-century Mediterranean diplomacy. It has caught the attention of numerous scholars ever since Gustave Schlumberger re-discovered Constance’s tomb in Valencia, in 1902, where she had died at the beginning of the fourteenth century after a long and eventful life. Yet, a number of questions on this union have been left unresolved: first and foremost, its dating, which is of great importance to fully understand the diplomatic process that made it possible; secondly, the precise nature of the ceremony that was performed on the occasion, which might reflect imperial marriage policies and shifting practices with respect to engagement and wedding; thirdly, the general silence of the sources, especially the Byzantine histories of the Nicaean period, on Constance and her time in Byzantine Anatolia. This article will move from the historical context that encompasses Constance’s arrival in Nicaea and propose a possible answer to all three questions.