Complex sentence: On 1 November 1940 an agency of the banking services was set up in Marseilles to serve the Free Zone, and in 1941 opened an agency in Algiers, which grew rapidly and continued to operate successfully after the Allied landings in November 1942.
Split into simpler sentences: On 1 November 1940 an agency of the banking services was set up in Marseilles to serve the Free Zone, and in 1941 opened an agency in Algiers, which grew rapidly. It continue to operate successfully after the Allied landings in November 1942.