Pakenham was the son of
Thomas Pakenham, 1st Baron Longford and
Elizabeth Cuffe, 1st Countess of Longford. His parents had seven children, including
Sir Thomas Pakenham, a
Royal Navy officer. His father was the eldest son and heir of
Edward Pakenham MP of Pakenham Hall (son of
Sir Thomas Pakenham) and Margaret Bradestan (daughter and heiress of John Bradestan). His mother was the daughter and sole heiress of
Michael Cuffe MP (second son and sole heir of
Francis Cuffe), and Frances (
née Sandford) Cuffe (a daughter of Henry Sandford of Castlereagh). Longford was educated at
Kilkenny College and joined the
Royal Navy at the age of sixteen. ==Career==