ألفونسو السادس ملك قشتالة
In late 1079, Constance remarried to Alfonso VI of León and Castile. The marriage appears to have been orchestrated via the Cluniac connections at Alfonso's court. He had previously been married to Agnes of Aquitaine, whom he had either divorced or had been widowed by. The marriage of Constance and Alfonso initially faced papal opposition, apparently due to a kinship between Constance and Agnes.