Final answer:
Napoleon's initial reluctance to leave Josephine was likely due to love and political convenience. As his need for a male heir grew to solidify his empire, he divorced Josephine to marry Marie-Louise of Austria, which also aimed to establish his own royal line.
Step-by-step explanation:
What kept Napoleon from leaving Josephine? Initially, it was likely love and political convenience that bound Napoleon to Josephine. However, as time progressed and the need for a male heir became paramount for solidifying his empire, Napoleon's motivations shifted.
In 1810, after several military successes and significant political moves, including an excommunication by Pope Pius VII, Napoleon decided to dissolve his marriage with Josephine since she was unable to provide him with an heir.
He then married Marie-Louise of Austria, which was both a strategic alliance and a step towards founding his own royal lineage. This decision was not without controversy, as it betrayed the revolutionary ideals and caused dissent among his ranks.
Nevertheless, the quest for an heir and maintaining the continuity of his empire outweighed his loyalty to Josephine.