In 1914, more than 1000 London buses carried soldiers to the Western front, some returning with the injured. Painted khaki and with the windows boarded up, their civilian drivers bravely drove them no faster than their top speed of 16mph to places far away from their traditional London streets.
Back to today, the B2737 has been completely restored thanks to the Heritage Lottery Fund and other donations. It is one of only four of its type in existence, originally running on route 9 from Mortlake garage.
This morning outside the London Transport Museum I cranked its starting handle, firing into life its petrol engine in front of the press and stakeholders. After photographs and interviews were done the bus was left on the Piazza to be enjoyed by visitors before heading off to its first event - the London Bus Awards.
It will compete a limited number of engagements in London this summer before being painted khaki - in public - in Central London. It will reprise its expedition to France and Belgium where it will attend numerous events connected with the 100th anniversary of World War I.
So for a short while the B2737 will be in its original red livery. Look out for it at the London Bus Cavalcade in Regent Street on 22 June.