Kammala jumla mai zuwa: A ranar 4 ga Agusta, 1914, 1st Battalion, East Surrey Regiment yana cikin Dublin. Kwana goma sha ɗaya bayan haka, an kammala tattarawa da kuma kafa cikakken yakin, Batun na 1 ya sauka a Le Havre a Faransa, kuma kafin karshen watan ya yi aiki da Jamus. An sanya bataliya zuwa Brigade na 14, Rukunin na 5, wani ɓangare na asalin rundunar BEF. A lokacin da aka janye daga Mons da kuma bayan haka, rundunar ta shiga cikin manyan fadace-fadace na 1914,
Le Cateau, da Marne da kuma Aisne. A shekara ta 1915, bayan yakin La Bassée, 1st East Surreys ya tsayayya da kai hari a kan Hill 60, kusa da Ypres. A cikin matsanancin fadace-fadace da suka biyo baya, bataliya ta sami Victoria Cross guda uku da lambar yabo guda bakwai. Daga cikin VCs akwai Lieutenant George Roupell, wanda daga baya ya zama Colonel na karshe na East Surrey Regiment. A ƙarshen 1915 an tura brigade zuwa sashin na 32. A cikin 1916, 1st Battalion ya shiga cikin manyan yaƙe-yaƙe na Kogin Somme, kuma ya bambanta kansa musamman a Morval a watan Satumba. Bataliya ta shiga cikin manyan yaƙe-yaƙe da yawa na 1917, kamar Arras, Yaƙin Ypres na Uku. Bayan yawon shakatawa na watanni hudu a kan Italiya Front, rundunar ta koma Faransa a watan Maris na 1918, kuma ta shiga cikin yakin Albert da Bapaume, da kuma ci gaba zuwa nasara.