1915. April, May, June.
At the end of April, Hill 60 near Ypres was taken by the Second Corps under Lieut.-General Sir Charles Fergusson, and was lost again early in May when the enemy used gas. The second battle of Ypres began on May 10, and will always be notorious for the treacherous use of poisonous gas by the Germans. The British Army was totally unprepared for this treachery, and had no gas helmets of any kind, yet such was the tenacious courage displayed by it that the Germans were unable to do more than drive the line back a certain distance. It was in this battle that the Canadians greatly distinguished themselves. The battle of Festubert was the principal offensive at the end of May, although there was continual fighting in other parts of the line.
On May 22 Italy joined the Allies, and declared war on the Central Powers. This was a great blow to the Germans, who had fondly hoped that Italy would remain at least neutral, and it completely altered the situation in Central Europe.
The Gallipoli Campaign commenced, and the British and French troops effected a landing at the extremity of the Peninsula near Krithia in April. In Mesopotamia operations against the Turks were carried forward under great difficulties, while a Turkish Army under the command of German officers made an unsuccessful attempt to cross the desert and attack Egypt. In German South-West Africa General Botha succeeded in pushing his way into the enemy's country, and in capturing a large number of prisoners.
The Zeppelin raids on London and the East Coast began, and as there were practically no defences at the time the Germans were able to carry them out with impunity.
In April the Russian Army continued its advance in Austria, but was gradually driven back by General von Mackensen's German Army. In the extreme north the Germans, supported by their Baltic Squadron, captured the Russian port of Libau. The Austrian Army was now being reorganised by the German General Staff, and by the end of June the combined Austrian and German Armies had recaptured Przemysl and Lemberg, and driven the Russians back over the frontier.
July, Aug., Sept.
With the exception of continual fighting round Ypres no serious operation was undertaken by the British Army until September, when the battle of Loos was fought.
The Russians were slowly driven out of Poland by the Germans, but had some successes in Galicia.
A second landing on the Gallipoli Peninsula was effected at Suvla Bay, and some farther advance was made later.