Britain publishes a list of contraband of war

On 4 August 1914 the British government issued a proclamation defining which goods would be treated as contraband of war. Contraband was the name given to goods that could help the enemy wage war and that could lawfully be seized at sea, including aboard ships of neutral countries.

The proclamation divided goods into two groups. The first was absolute contraband: weapons, ammunition, explosives and other military equipment, liable to confiscation if bound for an enemy country. The second was conditional contraband, that is, goods that could serve both the civilian population and the army, such as food, fuel or materials for production. These could be confiscated if it was proved that they were destined for the enemy’s armed forces or government.

This division followed the Declaration of London of 1909, which had tried to codify the law of naval warfare. Britain never ratified it, but in August 1914 agreed to apply it, with its own modifications. In the following months the contraband lists were extended many times, and the line between military and civilian goods became increasingly blurred.

The proclamation was the first step towards the naval blockade of Germany, one of Britain’s most important weapons in this war. Thanks to the superiority of the Royal Navy, the British could control shipping to German ports. The blockade gradually cut Germany off from raw materials and food, contributing to shortages and hunger in the last years of the war. It also caused tension with neutral countries, above all the United States, whose merchant ships were subject to inspection.