The Spanish Civil War had a deep impact on Gibraltarian society. On one hand, the British authorities, the Anglican and Catholic churches and the Gibraltarian moneyed class supported the Nationalists in the War, while the working class sided with the Republicans. With Europe sliding towards a general war, the British Government decided to strengthen Gibraltar's defences and upgrade the naval base to accommodate the latest generation of battleships and aircraft carriers. A Gibraltar Defence Force (now the Royal Gibraltar Regiment) was established in March 1939 to assist with home defence. Second World War The outbreak of the Second World War in September 1939 did not initially cause much disruption in Gibraltar, as Spain and Italy were neutral at the time. The situation changed drastically after April 1940 when Germany invaded France, with Italy joining the invasion in June 1940. The British Government feared that Spain would also enter the war and it was decided to evacuate the entire civilian population of Gibraltar in May 1940. Most went to the United Kingdom and others to Madeira and Jamaica, while some made their own way to Tangier and Spain. An intensive programme of tunnelling and refortification was undertaken; over of tunnels were dug in the Rock, and anti-aircraft batteries were installed in numerous locations in the territory. A new and powerful naval group called Force H was established at Gibraltar to control the entrance to the Mediterranean and support Allied forces in North Africa, the Mediterranean and the Atlantic. The airfield, which was now designated RAF North Front, was also extended using soil from the tunnelling works so that it could accommodate bomber aircraft being ferried to North Africa. The garrison was greatly expanded, reaching a peak of 17,000 in 1943 with another 20,000 sailors and airmen accommodated in Gibraltar at the same time. During the Battle of the Atlantic, Gibraltar played a key role. The Ocean Convoy System adopted by Britain after the fall of France in June 1940 ran on two routes – an east–west route between the UK and North America, and a north–south route between the UK, Gibraltar and Freetown in British-ruled Sierra Leone. Even before the war, Gibraltar had been designated as one of the main assembly points for convoys heading inbound to Europe. From late 1942, Gibraltar was the destination of the Central Atlantic convoy route between the United States and the Mediterranean in support of