Censorship is when written material is read and checked by another person. The censor deletes any sensitive or secret parts. Censorship is important during wars to stop the enemy uncovering secret information and plans if they capture the letters.
British sailors fighting in World War One wrote many letters home to their families. All these letters had to be censored. Officers censored letters using a black marker pen or sissors. They blacked or cut out anything they thought might help the enemy.
The address was been cut out of this letter. It is a letter sent by Terence Salter from HMS Sphinx to his mother and father. Between 1913 and 1915 he wrote home on a weekly basis. Most of this time was spent on patrol in the Persian Gulf. Duties included searching for arms and slaves and regulating pearl fisheries, these changed slightly with the outbreak of World War One.
Salter starts the letter by writing 'The Censorship is very strict here so I cont tell you where we are. However we are about 50 miles nearer to England than the nearest place to England I have mentioned in my letters recently.'
Flight Lieutenant J M D'Arcy Levy flew seaplanes during World War One in the Royal Naval Air Service. German ground fire shot him down over Zeebrugge and he became a prisoner of war . Find out more about Levy's life and time as a POW by reading more of his letters.
This postcard was censored by the Germans so that Levy could not give information to the British.
During the Falklands War some ships, for example HMS Abeuscade, censored letters. Other ships, for example HMS Glamorgam, chose not to.
Censorship was also used during World War Two. "Loose lips sink ships" was a common catchphrase used at this time to remind people to be careful what they said or wrote to others.