To "fight like a Kilkenny cat" refers to an old story about two cats who fought to the death and ate each other up such that only their tails were left. There is also a limerick (with optional added couplet) about the two cats:
- There once were two cats of Kilkenny
- Each thought there was one cat too many
- So they fought and they fit
- And they scratched and they bit
- Till (excepting their nails
- And the tips of their tails)
- Instead of two cats there weren't any!
The story has many roots. The most likely would need to date from the mid 17th century. The phrase was certainly in existence by 1657, since Cromwell references "Kilkenny cats" in his letters.
A local version of the story tells that in the mid 17th century Oliver Cromwell's soldiers tied the tails of all the cats in Kilkenny in pairs of two and hung them over a wire. The cats then fought until they had killed each other. The final cat was then beheaded..
It is said to be an allegory on the disastrous municipal quarrels of Kilkenny and Irishtown which lasted from the end of the 14th to the end of the 17th centuries. After the Statutes of Kilkenny the city was divided into two boroughs called Irishtown and Englishtown. For religious, cultural and political reasons there were deep divisions between the two groups. This may lend itself to the story of two cats fighting. Because the rights and duties of the two townships hadn't been made clear by statute this led to three centuries of dispute between the rival municipal bodies that ended in beggaring both of them.
The other most likely origin from this time suggests it was a commentary on the lack of agreement within the Kilkenny Confederates in the assembly.
Versions were told in detail in Notes & Queries. in 1864 it was said that a group of German soldiers (Hessians) were stationed in Kilkenny, during the period of the 1798 rebellion. To relieve the boredom in barracks, sadistic soldiers would tie two cats together by their tails, hang them over a washing line to fight and place bets on the "winning" cat. Gambling was contrary to military regulations, the story goes that the soldiers, alarmed by the impending arrival of an officer, released the cats by cutting their tails with a sword. When the officer arrived and inquired about the scene facing him, he was told that "they've eaten each other up" 
It is claimed to be the invention of J. P. Curran. As a sarcastic protest against cock-fighting in England, he declared that he had witnessed fights between trained cats, and that once they had fought so fiercely that only their tails were left.
Another story has a thousand Kilkenny cats fighting a thousand cats from the rest of Ireland in a field outside Kilkenny City. All the cats died in battle. This may be a parable based on dissents of the period between the people of the Kilkenny area and other parts of Ireland.
In popular culture
In David Webers Honor Harrington novel Echoes of Honor, wardens on the prison planet Hades use starvation of prisoners as an ultimate sanction for attempted insurrection, referring to each camps subsequent self-destruction from cannibalism as "Kilkenny Camps".
- "Literature". The Victorian Web. Retrieved February 11, 2013.
- Oliver Cromwell's Letters and Speeches: (X, 322 p.85).
- Notes and Queries, 1st series, vol. ii. p. 71.
- Trudy Ring, Noelle Watson, Paul Schellinger (2013). Northern Europe: International Dictionary of Historic Places. Routledge. pp. 900 pages.
- Notes and Queries 3rd series, vol. v. p. 433.
- Notes and Queries 7th series, vol. ii. p. 394.
- "The cats against Galway". Retrieved 11 February 2016.
|Wikisource has the text of a 1911 Encyclopædia Britannica article about Kilkenny cat.|