Born George Amyand, he was the eldest son and heir of Sir George Amyand, 1st Baronet (1720–1766) by his wife Anna Maria Korteen, daughter of John Abraham Korteen, a Hamburg merchant. In 1766 he succeeded his father as 2nd Baronet and inherited his interest in the banking firm of Amyand, Staples and Mercer.
Amyand was educated at Eton College then at Christ Church, Oxford, where he graduated Master of Arts in 1769.
In 1773 he received a Doctorate of Civil Law from the University of Oxford. Cornewall entered the British House of Commons in 1774, sitting for Herefordshire until 1796. He represented the constituency again in the Parliament of the United Kingdom between 1802 and 1807.
He served in the Herefordshire Militia and became its colonel in 1805.
He was owner of a plantation in Grenada, West Indies, and in 1775-1781 re-built Moccas Court, the family"s later residence in Herefordshire. He inherited Mouse Castle, Cusop but exchanged lieutenant
In 1800, he sold Frilsham, Berkshire, which his father had purchased in 1762, to Robert Hayward. He served as a Family Trustee of the British Museum from 1788 until his death.
Cornewall died in 1819 and was buried at Moccas.
2nd United Kingdom Parliament. 3rd United Kingdom Parliament. 14th Parliament of Great Britain.
15th Parliament of Great Britain.
16th Parliament of Great Britain. 17th Parliament of Great Britain.
