Under the longstanding sway of Pisa and Genoa over Corsica, Corsican used to play the role of a vernacular in combination with Italian, which was the island's official language. In 1859, Italian was replaced by French, owing to the French acquisition from the Republic of Genoa in 1768. Over the next two centuries, the use of French in the place of Italian grew to the extent that, by the Liberation in 1945, all the islanders had a working knowledge of French. The 20th century saw a language shift, with the islanders changing their language practices to the extent that there were no monolingual Corsican speakers left by the 1960s. By 1995, an estimated 65 percent of islanders had some degree of proficiency in Corsican, and a minority amounting to around 10 percent used Corsican as a first language.