Corsica the wars for the conquest of the colonial empire, the introduction of steamboats, which reduced the travel time between mainland France from the island drastically, and — last but not least — Napoleon himself, whose existence alone constituted an indissoluble link between France and Corsica. Thanks to all these factors by around 1870 Corsica had landed in the French cultural world. From the 19th century into the mid-20th century, Corsicans also grew closer to the French nation through participation in the French Empire. Compared to much of Metropolitan France, Corsica was poor and many Corsicans emigrated. While Corsicans emigrated globally,
Corsica French from the island and established an Anglo-Corsican Kingdom. Following Spain's entry into the war, the British decided to withdraw from Corsica in 1796. Corsica returned to French rule. Despite being the birthplace of the Emperor, who had supported Paoli in his youth, the island was neglected by Napoleon's government. In 1814, near the end of the Napoleonic Wars, Corsica was briefly occupied again by British troops. The Treaty of Bastia gave the British crown sovereignty over the island, but it was later repudiated by Lord Castlereagh who insisted that the island should be returned to a restored French monarchy.