After surviving a recent vote of no confidence, the PM finally bowed to pressure from his own party and resigned, giving a speech outside No10 Downing Street at lunchtime.
The race for the top job will now begin with a new PM expected to be appointed in the autumn.
Here we look back at some of Boris’ visits to Lancashire, including Preston, Blackpool, Leyland, Burnley and Accrington.
5. Making a point
Boris gets a tour at Talbot Gateway during a trip to Blackpool Photo: nw
6. Pipe dream
Boris being shown a pressurised cooker at Burnley College. Picture: Peter Byrne - WPA Pool/Getty Images Photo: getty
7. Ice to see you
Boris was on the local election campaign trail at Robinsons The Dairy Shop in Leyland. Picture by Andrew Parsons CCHQ / Parsons Media Photo: parsons
8. Goggles on
Boris at Burnley College. Picture by Andrew Parsons CCHQ / Parsons Media Photo: parsons