Short answers, pulled from the story.
The seven primary islands are Kerkyra, Paxi, Lefkada, Ithaki, Kefalonia, Zakynthos, and Kythera. These islands form a distinct historic region stretching across the sea west of mainland Greece.
Venice controlled Corfu starting from 1204 and gradually acquired all other islands by 1502. Zakynthos passed to Venice in 1482 while Kefalonia and Ithaki arrived in 1483 and Lefkada came later in 1502.
Britain established the United States of the Ionian Islands on the 5th of November 1815 under its protection. Islanders elected an Assembly of 40 members to advise the British High Commissioner beginning in January 1817.
The 1953 Ionian islands earthquake struck with surface wave magnitude of 7.2 on August 12. Maximum Mercalli intensity reached X classified as Extreme causing extensive building damage across the southern islands.
Kerkyra holds a population of 103,300 including Paxoi according to recent data. This island remains part of the Greek region called Ionian Islands despite Kythera belonging to Attica Region.