 Vanguard was laid down on 2 October 1941 by John Brown and Company of Clydebank , Scotland , with the yard number of 567 . After the Japanese invasion of Malaya in December , the ship was given an A1 priority in the hope of finishing her by the end of 1944 and construction of the light cruiser HMS Bellerophon , as well as some merchant shipping , was halted to expedite the ship 's completion . This was unsuccessful , however , due to a shortage of skilled labour . As a result , it was not until 30 November 1944 that the ship was launched . Princess Elizabeth presided over this ceremony , the first ship she ever launched , and was presented with a diamond rose brooch to commemorate the event . 
