World War 1 - 1915

'World War One - 1915' is the second of our five-part series covering the Great War. This episode covers one of the first strategic bombing raids in history, when two German Zeppelin airships bombed the British ports of King's Lynn and Great Yarmouth. At sea, the British Royal Navy won the Battle of Dogger Bank. Germany then announced an Exclusion Zone around the British Isles, where its U-boats waged 'unrestricted submarine warfare' against British ships.

On the Eastern Front, 1915 began with further success for German Field Marshal Paul von Hindenburg, defeating the Russians at the Second Battle of Masurian Lakes. But the Russians had their own success at Przemyśl, taking 100,000 Austro-Hungarian prisoners.

British and French battleships arrived at the Dardanelles, intending to force the Ottoman Empire to surrender by threatening its capital, Constantinople. But Turkish shore-forts and sea mines caused heavy losses amongst Allied ships. Troops landed at Gallipoli, including the Australian and New Zealand Army Corps (ANZACs), became pinned down by fierce Turkish resistance.

On the Western Front, the British attacked at Neuve Chapelle. Indian Army units played a major role, but the offensive ended in failure. A German attack at Ypres opened with the first use of chemical weapons on the Western Front.

In April, the Ottoman Empire began the arrest, deportation and execution of ethnic Armenians, whom they suspected of sympathising with Turkey's enemies. The events remain controversial, with the Turkish government arguing that the number of deaths has been exaggerated and cannot be described as 'genocide'. Most historians and many other national governments disagree, describing these events as the Armenian Genocide and placing the death-toll between 1 and 1.5 million.

At sea, British passenger ship RMS Lusitania was sunk by a U-boat, leading to 1,198 civilian deaths, including 128 Americans. President Woodrow Wilson and the American public were outraged. In response to American warnings, Germany agreed to suspend attacks on passenger ships.

A new Allied attempt to break the Western Front stalemate at the Second Battle of Artois ended with heavy losses, after failed attacks at Vimy Ridge, Aubers Ridge and Festubert. In the air, Germany gained air superiority thanks to the Fokker Eindecker, a monoplane armed with a forward-firing machine-gun.

In June 1915 Italy joined the war, attacking Austria-Hungary in the first of many battles of the Isonzo River. At Gallipoli, the Allies failed to break the stalemate with new landings at Suvla Bay and a series of attacks known as the Battle of Sari Bair (including ANZAC assaults at Lone Pine and the Nek.)

France and Britain launched their Great Autumn Offensive to relieve pressure on their Russian ally. But French attacks at the Third Battle of Artois and Second Battle of Champagne, as well as a British attack at the Battle of Loos, led to massive losses with few significant gains.

In the Balkans, the Allies landed troops at Salonika in Greece, hoping to bring aid to Serbia. But when Bulgaria entered the war on the side of the Central Powers, Serbian forces were outflanked and outnumbered. Belgrade fell, and Serbia was overrun. The Serbian army fled through the Albanian mountains, but suffered catastrophic losses from hunger and cold.

CORRECTION: the map shows Cyprus as part of the Ottoman Empire. Cyprus was part of the Ottoman Empire from 1570 to 1914, but when the Ottoman Empire joined the Central Powers in November 1914, Cyprus was annexed by Britain.