Backman returned to England in 1933, having won a fellowship to Imperial College, where he joined Sydney Chapman’s Mathematics Department. Here, he worked on lattice theory for two years, after which he was awarded a PhD, his second doctorate. Blackman then succeeded in obtaining an industrial research senior research award from the DSIR, enabling to undertake research in Cambridge and register for a third doctorate. He worked on the detail of the Born-von Karman crystal lattice, resulting in another PhD. He was very soon invited back to Imperial College by George Thomson. He joined the Physics Department as an assistant lecturer in 1937, and was soon seen as the theoretical physicist of the Department.