Final answer:
Napoleon Bonaparte invaded Russia to expand the French empire and regain lost popularity. His ultimate goal was to conquer Russia and the European part of the Ottoman Empire under French rule.
Step-by-step explanation:
Napoleon Bonaparte invaded Russia to expand the French empire. He saw Russia as the last major power on the continent that opposed him and saw an opportunity to regain lost popularity and expand his empire's borders. Napoleon's ultimate goal was to conquer not just Russia, but also the European part of the Ottoman Empire, re-creating most of the ancient Roman Empire under French rule.