His name, sometimes given as Peter de Colechurch, is connected to the church where he was a priest, St Mary Colechurch in Cheapside.
Colechurch had already rebuilt London Bridge from elm in about 1163. Then in 1176 he began work on the foundations for the first pier of a new stone bridge. This work was probably instigated by King Henry II. The eleventh pier from the Southwark side was built as the largest of the nineteen piers, specifically to accommodate a chapel dedicated to Thomas Becket. Most Londoners on pilgrimage to Canterbury would have begun their journey by crossing the bridge. In 1205 Peter of Colechurch was buried in this chapel.
The bridge took 33 years to complete (Colechurch died before it was completed) and lasted more than 600 years.
Our information is mainly from various Wikipedia pages and British History online.