Henry Cooke came of a family of puritan settlers in County Down from Devonshire. He was the youngest son of John Cooke, tenant farmer of Grillagh, near Maghera, County Londonderry, by his second wife, Jane Howie or Howe, of Scottish descent, and was born on 11 May 1788. From his mother he derived his force of character, his remarkable memory, and his powers of sarcasm. A vivid impression, retained through life, of the events of 1798—the Irish Rebellion—influenced his political principles. After struggling for an education in rude country schools, he matriculated at Glasgow College in November 1802. Owing to illness he did not graduate, but he completed the arts and divinity courses, not shining as a student, but taking immense pains to qualify himself as a public speaker. Fresh from Glasgow, he appeared before the Ballymena presbytery in the somewhat unclerical attire of blue coat, drab vest, white cord breeches and tops, proved his orthodoxy on trial, and was licensed to preach.