With additional Czech pilots arriving from France during the summer of 1940 the RAF decided, after the formation of No.310 (Czech) Squadron, to establish a second Czech fighter unit as No.312 Squadron. It quickly gained operational status and participated in the last phase of the Battle of Britain before experiencing all the ups and downs of Fighter Command’s activities over the following years. It was briefly part of the 2nd TAF and took part in the D-Day landings. During its existence 145 pilots served with the squadron. This is a companion to the No.310 Squadron book and has 75 photos and 10 colour profiles showing the various types used during five years.