LONDON — Seven decades after Hitler’s forces began targeting the citizens of Britain, a memorial service is being held to honor those who protected London during the Blitz.

Firefighters, Royal Air Force personnel, nurses and ambulance staff who were in the city in 1940 are to attend Tuesday’s service at St. Paul’s Cathedral in central London.

The German bombing campaign began September 7, 1940, and continued until May 1941.

The service will be followed by a parade and a flyover by the RAF’s Battle of Britain Memorial Flight, which is made up of a Spitfire, a Lancaster bomber, and a Dakota aircraft.

Earlier this week, Westminster Council released rare color footage showing bomb damage inflicted on London during World War II.