The Irish have used various sticks and cudgels as weapons of self-defense for centuries. As with most vernacular martial arts, it is difficult to establish the origin of the art. The art certainly goes back to prehistory and possibly was widespread in the Bronze Age when metal was highly precious yet sticks were easily obtained. Weapons similar to shillelagh are described in various sources including heroic tales such as The Destruction of Da Derga's Hostel. It would truly begin to catch the attention of writers in the 18th century. The shillelagh is still identified with Irish popular culture to this day, although the arts of bataireacht are much less so. The sticks used for bataireacht are not of a standardized size, as there are various styles of bataireacht, using various kinds of sticks.
By the 18th century bataireacht became increasingly associated with Irish gangs called "factions". Irish faction fights involved large groups of men (and sometimes women) who engaged in melees at county fairs, weddings, funerals, or any other convenient gathering. Historians such as Carolyn Conley, believe that this reflected a culture of recreational violence. It is also argued that faction fighting had class and political overtones, as depicted for example in the works of William Carleton and James S. Donnelly, Jr.'s "Irish Peasants: Violence & Political Unrest, 1780".
By the early 19th century, these gangs had organized into larger regional federations, which coalesced from the old Whiteboys, into the Caravat and Shanavest factions. Beginning in Munster the Caravat and Shanavest "war" erupted sporadically throughout the 19th century and caused some serious disturbances.
As the faction fights became increasingly repressed and other sports such as hurling were promoted, bataireacht slowly faded away by the turn of the 20th century. Although still documented sporadically, it has become mostly an underground practice saved by a few families who still handed down their own styles.
The modern practice of bataireacht has arisen amongst some practitioners from a desire to maintain or reinstate Irish family traditions, while for others a combination of historical and cultural interest has led to their interest. Bataireacht has also gained popularity amongst non-Irish people, especially in North America, as a form of self-defense, as a cane or walking stick can be easily carried in modern society.
A few forms of bataireacht survive to this day, some of which are traditional styles specific to the family which carried them down through the years, like the rince an bhata uisce bheatha ('dance [of] the whiskey stick') style of the Doyle family of Newfoundland, taught in Canada, Ireland, the United Kingdom, the United States, Germany, and Mexico.
Additionally, members of the Western martial arts movement have "reconstructed" styles using period martial arts manuals, historical newspaper articles, magazines, pictorial evidence and court documents.
Sources: Bataireacht - Wikipedia (EDITED FOR CONTENT)