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.
. bozinbpool3.jpg
Boris Johnson during his speech at Blackpool and The Fylde College Photo: Peter Byrne
. Jog on
Boris Johnson runs on Blackpool Beach during his time in the resort for the Conservative Party conference earlier this year. Photograph credit: Conservative Party/ @Conservatives Photo: cp
. Platform PM
Boris at Preston train station. Picture by Andrew Parsons CCHQ / Parsons Media Photo: parsons
. The eyes have it
Boris Johnson meeting a student at Blackpool and The Fylde College Photo: nw
. Hair today, gone tomorrow
Boris with a student at Blackpool and The Fylde College Photo: nw
1. Jog on
Boris Johnson runs on Blackpool Beach during his time in the resort for the Conservative Party conference earlier this year. Photograph credit: Conservative Party/ @Conservatives Photo: cp
2. Platform PM
Boris at Preston train station. Picture by Andrew Parsons CCHQ / Parsons Media Photo: parsons
3. The eyes have it
Boris Johnson meeting a student at Blackpool and The Fylde College Photo: nw
4. Hair today, gone tomorrow
Boris with a student at Blackpool and The Fylde College Photo: nw