The 381 started life as the P11, following much of the same route, with only a few diversions. The P11 "Peckham Hopper" itself was a renumbering of the Peckham to Waterloo section of the 70/70A routes on 19 November 1988. The other sections covered by route P12 and new roads served by route P13, creating a new Peckham network of minibus routes, using Optare StarRider-bodied Mercedes-Benz 811D 26 seater minibuses. Those on the P11 were replaced in 1991 by new, larger, Dennis Darts, but these were still not big enough, and the P11 was eventually converted to double-deck using 9 Volvo Olympians and 5 Leyland Titans in 1995.
The P11 was renumbered 381 in September 1999, so that a night route N381 (running beyond Waterloo to Trafalgar Square via Westminster Bridge) could be added - rather than a potentially confusing NP11. After ten years London Central lost the contract to Travel London, who took over the route on 9 October 2004.
The route almost loops back on itself several times.[1]
In February 2008, the service gained an extra three buses to run between London Bridge and Canada Water, increasing the frequency of the route by an additional bus every 20 minutes over the section. This replaced the withdrawn route ELP while the East London Line was closed.[2]
