Cap badge, other ranks, Royal Corps of Signals, 1940 (c)

Badge with a figure of the Roman god Mercury within an oval, bearing the unit title, 'Royal Corps of Signals', surmounted by a crown.

For many years, British Army units undertook their own signalling duties. The first professional body of signallers arose in 1870, when Captain Montague Lambert formed 'C' Telegraph Troop within the Royal Engineers. The Army's signallers only became a corps of their own in 1920, instantly gaining the 'Royal' prefix. The Royal Corps of Signals was assigned a place in the order of precedence between the Royal Engineers and the Foot Guards.

The badge of the Royal Corps of Signals depicts Mercury, the winged messenger of the gods, holding a caduceus (herald's staff) in his left hand, while balancing on a globe. In 1947 the motto of the Corps, 'Certa Cito' meaning 'Swift and Sure', was included in a new badge design.