COWPER, WILLIAM COWPER, 1ST EARL (c. 1665 1723), lord chancellor of England, was the son of Sir William Cowper, Bart., of Ratling Court, Kent, a Whig member of par liament of some mark in the two last Stuart reigns. Educated at St. Albans school, Cowper was called to the bar in 1688; having promptly given his allegiance to the prince of Orange on his land ing in England, he was made recorder of Colchester in 1694, and at various times represented Hertford and other constituencies in parliament. He enjoyed a large practice at the bar, and had the reputation of being one of the most effective parliamentary orators of his generation. It was in 1705 that he was appointed lord keeper of the great seal, and took his seat on the woolsack without a peerage. In the following year he conducted the nego tiations between the English and Scottish commissioners for arranging the unicn with Scotland. In November of the same year (1706) he succeeded to his father's baronetcy; and on Dec. 14 he was raised to the peerage as Baron Cowper of Wingham, Kent.
When the union with Scotland came into operation in May 1707 the queen in council named Cowper lord high chancellor of Great Britain, he being the first to hold this office. He pre sided at the trial of Dr. Sacheverell in 171o, but resigned the seal when Harley and Bolingbroke took office in the same year. On the death of Queen Anne, George I. appointed Cowper one of the lords justices for governing the country during the king's absence, and a few weeks later he again became lord chancellor. A paper which he drew up for the guidance of the new king on constitutional matters, entitled An Impartial History of Parties, marks the advance of English opinion towards party government in the modern sense. It was published by Lord Campbell in his Lives of the Lord Chancellors. Cowper supported the impeach ment of Lord Oxford for high treason in 1715, and in 1716 pre sided as lord high steward at the trials of the peers charged with complicity in the Jacobite rising. He warmly supported the septennial bill in the same year. On March 18, 1718, he was created Viscount Fordwich and Earl Cowper, and a month later he resigned office on the plea of ill-health, but probably in reality because George I. accused him of espousing the prince of Wales's side in his quarrel with the king. He died at Colne Green, built by himself on the site of the present mansion of Panshanger, on Oct. Io, 1723.
Cowper was not a great lawyer, but Burnet says that "he managed the court of chancery with impartial justice and great despatch"; one or two of his judgments settled important points in real property law. He was twice married. His brother, Spencer Cowper (1669-1728), was grandfather of William Cowper, the poet.