In the beginning of the 20th century, Europe was overflowing from its frontiers. Economical rivalry, imperialism and nationalist movements were dividing the continent into two blocs. The conflict was rising between Germany-France and Russia-Austria. The tension in Europe had reached its highest point on 28 June 1914 with assassination of Archduke Ferdinand heir of the Austro-Hungarian throne by a Serbian nationalist.

On 28 July 1914, Austria had declared mobilisation then the Great War began. In Europe, two blocs had appeared, Central Powers (Germany, Austro-Hungary and Italy) and Triple Alliance (Britain, France and Russia). With the outbreak of the war, Italy had declared her neutrality but one year later she joined to the Triple Alliance.

On the other hand, Ottoman Empire was losing her large territories in which many nations and beliefs had lived for over 600 years. Both internal and external conflicts and wars were weakening her strength. Finally, Ottoman Empire with series of military defeats in Tripoli and in the Balkans lost nearly all her territories in Europe except the Trace.

Moreover, she lost her power and international prestige. From now on, the death of the empire was certain and European powers were planing to share the heritage. As seen, the Twentieth Century had compelled the Turks to grant zones of influence to European powers: Britain (Egypt-Palestine), France (Syria and the Lebanon), Austria-Hungary (Bosnia-Herzegovina), Italy (Libya). Russia was interested in the Mediterranean and Italy wanted parts of the eastern Mediterranean.

Following the blow of the war, under threat from within and outside her borders, Turkey sought a protective agreement from one of the two European power blocs: the Triple Alliance or the Central Powers. At first, she intended to join the Triple Alliance but Russia's protests led her to make a defensive alliance with Germany. On 2 August 1914, Turkey and Germany had signed a secret agreement.

Thereupon, the Turkish government had declared that it would remain neutral. However, to secure its borders, it introduced mobilisation. On 10 August 1914, Turkey allowed two German cruisers Goeben and Breslau, which were running from the Allied Navy, to enter the straits. Afterwards, she closed the straits to the foreign ships.

The Allies became increasingly alarmed with the arrival of those German ships. The Turkish government had stated that, they bought these battleships from Germany in place of two dreadnought battleships, which had been built in Britain for the Turkish Navy, and were requisitioned by Britain although Turkey had purchased them. Thus, the German ships became a part of the Turkish Navy with Turkish names, Yavuz and Midilli.

On 27 September 1914, Yavuz under the command of German Admiral Souchon bombarded Sivastopol and Novoroski, Russian shore establishments on the Black Sea. Thereupon, Russia passed the Caucasus border and declared war. This was the final act; the Ottoman Government was now at war.

Turkey's geographical position was crucial, the Bosphorus and the Dardanelles were significant, as they were the only passages between the Black Sea and the Mediterranean. Moreover, they were Russia's main contact with her allies, Britain and France.

In the course of history, countless wars had been fought for the straits in the name of their strategic positions, economic and cultural heritages. Even today, they still preserve their importance.

The Triple Alliance's attempt to pass the straits was certainly a direct result of their strategic positions. The allies' main target was to assist Russia. Likewise, it was believed that the capture of the straits would lead the British fleet to Istanbul and this might cause the downfall of the Turkish government. Further, it was hoped that the neutral European countries would join the Alliance against the Central Powers.

If the straits would be openned, this victory would intimidate all the Muslim colonies. All the events, disturbing the British would disappear.

Under these circumstances, Britain had decided to declare a war on 28 January 1915 and France offered a naval squadron to serve under British command in this great enterprise against Istanbul.