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 was divided in "pagi", which in the Middle Ages became the "pievi", the basic administrative units of the island until 1768. During the diffusion of Christianity, which arrived quite early from Rome and the Tuscan harbors, Corsica was home to many martyrs and saints: among them, the most important are Saint Devota and Saint Julia, both patrons of the island. Corsica was integrated into Roman Italy by Emperor Diocletian (r. 284-305). In the 5th century, the western half of the Roman Empire collapsed, and the island was invaded by the Vandals and the Ostrogoths. Briefly recovered by the Byzantines, it