Ionian Islands in Venetian hands since 1238. The islands thus became the only part of the Greek-speaking world to escape Ottoman rule, which gave them both a unity and an importance in Greek history they would otherwise not have had. Corfu was the only Greek island never conquered by the Turks. Under Venetian rule, many of the upper classes spoke Italian (or Venetian in some cases) and converted to Roman Catholicism, but the majority remained Greek ethnically, linguistically, and religiously. In the 18th century, a Greek national independence movement began to emerge, and the free status of the Ionian islands made them
United States of the Ionian Islands and Russia signed the Treaty of London, pledging the transfer of sovereignty to Greece upon ratification; this was meant to bolster the reign of the newly installed King George I of Greece. Thus, on 28 May, by proclamation of the Lord High Commissioner, the Ionian Islands were united with Greece. According to the second constitution of the republic (1803), Greek was the primary official language, in contrast to the situation in the Septinsular Republic. Italian was still in use, though, mainly for official purposes since the Venetian Republic. The only island in which Italian (Venetian) had a wider spread was