Constance was originally betrothed to Prince Robert, youngest son of Philip IV of France and Joan I of Navarre.
King Philip sent Constance's father a sorrowful letter announcing the news.
On 29 December 1331 Constance married her second husband Leo IV, King of Armenia.
Leo was strongly pro-Western because he favoured a union of the Armenian and Roman churches, which deeply displeased the native barons.
In Armenia, Constance was frequently ill, suffering from constant coughing, fatigue, and dizziness.