Page "Timeline of the history of Gibraltar" Paragraph 127

During World War II ( 1939 – 1945 ) the Rock was again turned into a fortress and the civilian residents of Gibraltar were evacuated.

Initially, in May 1940, 16, 700 people went to French Morocco.

However, after the French-German Armistice and the subsequent destruction of the French fleet at Mers-el-Kebir, Algeria by the British Navy in July 1940, the French-Moroccan authorities asked all Gibraltarian evacuees to be removed.

12, 000 went to Britain, while about 3, 000 went to Madeira or Jamaica, with the rest moving to Spain or Tanger.

Control of Gibraltar gave the Allied Powers control of the entry to the Mediterranean Sea ( the other side of the Strait being Spanish territory, and thus non-belligerent ).

The Rock was a key part of the Allied supply lines to Malta and North Africa and base of the British Navy Force H, and prior to the war the racecourse on the isthmus was converted into an airbase and a concrete runway constructed ( 1938 ).

The repatriation of the civilians started in 1944 and proceeded until 1951, causing considerable suffering and frustration.

However, most of the population had returned by 1946.