During World War II, Mansergh served with the Royal Artillery in Eritrea, Abyssinia, the Western Desert of Libya, the Middle East, Persia, Iraq, Arakan, Assam and Burma.
Selama Perang Dunia II, Mansergh bertugas bersama Artileri Kerajaan di Eritrea, Abessinia, Gurun Barat Libya, Timur Tengah, Persia, Irak, Arakan, Assam dan Burma.