 Their formation was followed in 1914 by the establishment of the Irish Volunteers , whose aim was to ensure that the Home Rule Bill was passed . The Act was passed but with the " temporary " exclusion of the six counties of Ulster that would become Northern Ireland . Before it could be implemented , however , the Act was suspended for the duration of the First World War . The Irish Volunteers split into two groups . The majority , approximately 175 @,@ 000 in number , under John <unk> , took the name National Volunteers and supported Irish involvement in the war . A minority , approximately 13 @,@ 000 , retained the Irish Volunteers ' name , and opposed Ireland 's involvement in the war . 
