The 2nd Dublins took part in all but one of the subsidiary battles during Second Ypres that took place between 22 April – 24 May 1915. The Battalion suffered heavily at the Battle of St Julien, the second subsidiary battle, incurring hundreds of casualties. They had no respite, taking part in the next two subsidiary battles at Frezenberg and Bellewaarde. On 24 May the Battalion was subject to a German poison gas attack near Saint-Julien and effectively disintegrated as a fighting unit. The British at that time had no defences against gas attack; indeed the large-scale use of gas by the Germans on the Western Front had begun at Second Ypres. The 2nd Dublins' commanding officer, Lieutenant Colonel Arthur Loveband of Naas, died the following day. The Battalion did not take part in any more major battles for the rest of the year.