Now that Sir Keir Starmer has unilaterally decided to give up British ownership of the Chagos Islands, the last vestige of our imperial inheritance in the Indian Ocean, it seems an appropriate moment to look back at the long-forgotten history of this remote possession. Mauritius will be the happy recipient of the Chagos Archipelago, which consist of some 60 islands, mainly low-lying atolls and their lagoons.