The Battle of Kellistown was fought on this day between the forces of the English led by Roger Mortimer, 4th Earl of March against the O'Byrnes and O'Tooles under the command of Art Óg mac Murchadha Caomhánach, the most powerful Chieftain in Leinster.

The English people are an ethnic group and nation native to England, who speak the English language, a West Germanic language, and share a common ancestry, history, and culture. The English identity began with the Anglo-Saxons, when they were known as the Angelcynn, meaning "Angle kin" or "English people". Their ethnonym is derived from the Angles, one of the Germanic peoples who invaded Britain around the 5th century AD.

Roger de Mortimer, 4th Earl of March, 6th Earl of Ulster was an English nobleman. He was considered the heir presumptive to King Richard II, his mother's first cousin, which made him a great-grandson of King Edward III.

Art Óg Mac Murchadha Caomhánach was an Irish king who is generally regarded as the most formidable of the later kings of Leinster. He revived not only the royal family's prerogatives, but also their lands and power. During his 42-year reign, he dominated the Anglo-Norman settlers of Leinster. His dominance of the province and its inhabitants, both Gaelic and Hiberno-Norman, was deemed sufficiently detrimental to the colony that Richard II of England spent much of the years 1394 and 1395 sparring with him. While MacMurrough-Kavanagh did eventually submit to Richard, he renounced this fealty on Richard's departure and made much of his kingdom a death trap for any invading English or Anglo-Irish forces. The Crown accordingly dealt with him cautiously and he was granted an amnesty in 1409.