O'Callaghan John Cornelius

John Cornelius O'Callaghan (1805 – 24 April 1883) was an Irish historian and writer. He is best remembered for his work History of the Irish Brigades in the Service of France.

O'Callaghan was born in Dublin. His father was a solicitor from Talbot St. in the city; his mother (née Donovan) came from the south of the country. He was educated at Clongowes Wood and later at a school in Blanchardstown