He was the eldest son of Edward Chichester, 1st Viscount Chichester, and made a career as a soldier before being elected to the Irish House of Commons as Member of Parliament for Armagh in 1634 and again in 1640.
Having distinguished himself in helping to put down the rebellion that took place in Ulster in 1641, Chichester was admitted to the Privy Council of Ireland in 1643 and appointed Governor of Belfast. It was on the advice of the Duke of Ormonde, Lord Lieutenant of Ireland at the time, that he was in 1647 created Earl of Donegall in the Peerage of Ireland. The title was created with a special remainder to the male heirs of his father, whom he succeeded a year later as second Viscount Chichester. He took his seat in the Irish House of Lords in 1661. In 1668 he endowed a mathematical lectureship at Trinity College, Dublin with an annuity of 30 livre (pounds), this lectureship survives as an annual public lecture at the School of Mathematics in Trinity College.
|Peerage of Ireland|
|New creation||Earl of Donegall
1648 – 1675
1647 – 1675