Declaration of London

The Declaration of London is a code of the law of naval war signed in London in 1909. It laid down when a warship could stop a neutral ship, what counted as contraband and how a blockade was to be conducted. No one ratified it, so it never came into force, but in the first two years of the war it was the point of reference in every dispute over neutral trade with Germany.

A code no one adopted

The naval conference was called by the British government and sat in London from 4 December 1908. The declaration was signed on 26 February 1909 by ten states, among them Britain, Germany, France, Russia and the United States. It was meant to be the law applied by a planned International Prize Court in The Hague. It divided goods into three groups: absolute contraband, above all arms and ammunition; conditional contraband, for example food; and goods that could not be declared contraband at all, such as rubber or metallic ores.

The restrictions on the navy caused the most controversy. Under Article 35 conditional contraband could be seized only on a ship bound for the enemy, not for a neutral port from which the goods might travel on overland. Article 19 did not allow a ship heading for an unblockaded port to be captured for breach of blockade, whatever the further destination of her cargo. British critics, among them the naval historian Julian Corbett, argued that the declaration took away the navy’s most effective weapon in economic warfare. On 12 December 1911 the House of Lords, by 145 votes to 53, rejected the Naval Prize Bill, which was meant to put the declaration into effect.

The declaration with changes

On 6 August 1914 the United States asked the belligerents whether they would apply the declaration if all sides accepted it. Germany agreed on condition of reciprocity. Britain on 20 August and France on 25 August announced that they would apply it, but with changes. The most important introduced the doctrine of continuous voyage: a cargo bound for the neutral Netherlands or Denmark could be seized if it was in fact destined for Germany.

All autumn the Americans urged London to accept the declaration without reservations. The British refused, because they wanted to declare rubber and iron ore, among other goods, contraband. On 22 October 1914 Washington withdrew its proposal and from then on defended neutral rights case by case. On 29 October London issued a new order and contraband lists, and on 13 November the Netherlands protested.

The Germans invoked the declaration too. It allowed a captured neutral ship to be sunk, instead of being taken before a prize court, only in exceptional circumstances. In January 1915 the auxiliary cruiser Prinz Eitel Friedrich sank the American barque William P. Frye, and in March U-28 sank the Dutch steamer Medea with oranges for London. To the Dutch protest Berlin replied that it had acted in accordance with the declaration.

The end of the declaration

Successive British orders, of October 1915 and March 1916, departed further and further from the declaration. The Minister of Blockade, Lord Robert Cecil, concluded that constantly amending it did most to feed the distrust of the neutrals. On 7 July 1916 Britain and France stopped applying it and announced that they would follow only the recognised principles of the law of nations. Russia did the same on 20 July, and Germany responded by changing its prize regulations. In practice little changed, because neutral trade with Germany was by then controlled mainly through agreements with merchants and the black lists.