Italy declares a blockade of the Austro-Hungarian coast

On 26 May 1915, three days after declaring war on Austria-Hungary, the Italian government declared a blockade of the enemy’s coasts. The declaration, circulated by the foreign ministry in Rome to the missions of foreign states, was in force from 26 May. It covered the whole Austro-Hungarian coast from the frontier with Italy in the north to the frontier with Montenegro in the south, “with all its ports, islands, harbours, roadsteads and bays”, and the coast of Albania from the Montenegrin frontier to Cape Kefali (Kephali) in the south of the country. The coast of allied Montenegro was excluded from the blockade.

Why Albania too

Albania was not taking part in the war. Since the departure of Prince Wilhelm of Wied in the autumn of 1914 it had been sunk in chaos, and the Italians had already occupied the port of Vlorë in December. In the declaration the Italian government justified including the Albanian coast in the blockade on the grounds that the Austro-Hungarian naval authorities were secretly supplying their ships in certain Albanian ports. Until then the French fleet, which had been guarding the exit from the Adriatic since August 1914, had in practice been maintaining a blockade on the line of the Strait of Otranto. Now Italy, as a state at war with Austria-Hungary, declared the blockade formally and gave it a legal framework.

The declaration defined the exact limits of both blockaded sections by geographical coordinates. Any ship that crossed the line closed between Cape Otranto and Cape Kefali was to be treated in accordance with international law and the treaties in force, which in practice meant detention and possible confiscation. Ships of allied and neutral states were to be given time to leave the zone freely, its length to be fixed by the commander of the Italian fleet. In the following days Rome clarified the rules: ships were given ten days from the declaration of the blockade, and the southern end of the Albanian section was moved slightly north, to a place called Aspri Ruga.

A closed sea

The blockade was of political and legal rather than practical significance. Austro-Hungarian merchant ships had in any case been unable to sail beyond the Adriatic since August 1914, and in the first days of the war the Italian fleet was only beginning operations in the Adriatic. The inclusion of neutral Albania in the blockade caused the most controversy. At the beginning of July 1915 Italy extended the blockade to the whole Adriatic north of the Otranto–Aspri Ruga line, practically closing that sea to shipping without Italian permission.

The United States considered these measures unlawful. In November 1915 the Secretary of State, Robert Lansing, wrote to the ambassador in Rome that according to the Declaration of London a blockade of the coast of a belligerent state could not extend to the coast of a neutral state. Washington announced that it would not recognise the Italian decrees and would claim compensation for any losses to American trade. Despite the protests the blockade of the Adriatic remained in force until the end of the war, and its most important element became the barrage in the Strait of Otranto, which was meant to close the way to the Mediterranean to Austro-Hungarian and German submarines.