Issued at the start of the First World War, the Treasury introduced the first 10/- note to replace the sovereign and half-sovereign gold coins. The first Bank of England ten shilling note (10/-) was introduced with a red-brown colouration in 1928, when Britannia was added (the first notes to be coloured and printed on both sides), and these notes were identifiable by the signature of the current Chief Cashier (on the note) rather than being specifically dated. A metal ‘security’ thread was added in 1940 alongside a colour change to mauve – to combat German counterfeits during the war. The ‘Series C’ design, the first with the Queen Elizabeth II portrait, was introduced in 1961. A ‘Series D’ design was planned – which would feature Sir Walter Raleigh on the reverse side (it was known as the ‘Pictorial Series’) – but due to the limited lifespan this note would have (as it would be replaced by the 50p coin as part of decimalisation), it was not issued. Following the introduction of the 50p coin in 1969, the ten shilling note was withdrawn from circulation in 1970.