United States of the Ionian Islands took Lefkada in 1810. The island of Corfu remained occupied by the French until 1814. The Congress of Vienna agreed to place the Ionian Islands under the exclusive "amical protection" of the United Kingdom. Despite British military administration, the Austrian Empire was guaranteed commercial status equal to the UK. The arrangement was formalised with the ratification of the "Maitland constitution" on 26 August 1817, which created a federation of the seven islands, with Lieutenant-General Sir Thomas Maitland its first "Lord High Commissioner of the Ionian Islands". The Party of Radicals (Greek: Κόμμα των Ριζοσπαστών) founded in 1848 was against the
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