"has never had to be challenged, although refined and extended". Bruce-Mitford's work also influenced him, decades later, to create a national reference collection of medieval pottery at the British Museum. British Museum In December 1937, Bruce-Mitford was named assistant keeper (second class) of the then Department of British and Medieval Antiquities at the British Museum. He was possibly helped in this position by his professor from two years previously, Robin Flower, also the deputy keeper of Manuscripts. The following year Bruce-Mitford was reacquainted with archaeological work, spending three weeks with Gerhard Bersu at the Iron Age site Little Woodbury. "I learned a lot", he later wrote, "and loved being out on the chalk, in the fresh air." There Bruce-Mitford met Charles Phillips, the secretary of The Prehistoric Society (for which Bersu was digging). In 1939 Bruce-Mitford was tasked with leading an excavation, this time at the medieval village of Seacourt. Though Seacourt was a difficult site, Bruce-Mitford thought it would be able to acquire complete ground plans of domestic buildings and of the church. It was also, he wrote, "a village deserted, in ruins, and archaeologically sealed within a century of the Black Death"; this precise dating—the village was deserted by 1439—"promised to provide important evidence for specialists in connexion with the chronology of mediaeval pottery and small objects" such as "brooches, ornaments, buckles, fittings of various kinds, shears, horseshoes, [and] nails" the dating of which was "notoriously vague". Excavations wrapped up 15 July 1939, seven weeks before Britain's entry into the Second World War. Second World War From 1940 to 1946, Bruce-Mitford served in the Royal Corps of Signals. Joining as a lance corporal and initially assigned to a territorial unit in Essex, he transmitted morse code during the day, after which he watched for fires from the dome of St Paul's Cathedral. He was in Catterick Camp in North Yorkshire by autumn, when The Yorkshire Archæological Journal reported that he and his friends cleared out a hypocaust at Middleham, "made plans and took photographs, and, while confirming [John] Topham's observations [from a 1882 excavation], added several important details". The photographs were taken by Eric Lomax. Bruce-Mitford was commissioned as a second lieutenant on 1 February 1941, a first lieutenant on 1 August 1942, an acting captain on 20 November 1942, and a temporary captain on 26 February 1943. By 1943 he was working on the publications staff of