He was made Baron Harley, of Wigmore in the County of Hereford, at the same time, also in the Peerage of Great Britain and with similar remainder as for the earldom.

[1] The style Earl of Oxford and Earl Mortimer was chosen because the ancient earldom of Oxford, held for many centuries by the de Vere family, had become dormant but not extinct in 1703, meaning a descendant could conceivably have stepped forward to claim his title.

Harley claimed the Oxford title because of his relationship through marriage to the de Veres.

His only surviving son, from his first marriage, was Sir Robert Harley, who was Master of the Mint for King Charles I.

His third wife was Lady Brilliana, a celebrated letter-writer and daughter of The 1st Viscount Conway.

Her mother, Dorothy, was the daughter of Sir John Tracy, and the sister of Mary, wife of General The 1st Baron Vere of Tilbury, through whom the Harley family became connected with the de Veres of the Earls of Oxford.

[2] Lord Oxford and Mortimer was succeeded by his only son, Edward, the second Earl, who married Henrietta Holles, daughter and heiress of The 1st Duke of Newcastle-upon-Tyne.

He was the son of Edward Harley, brother of the first Earl, and sat as Member of Parliament for Leominster and Droitwich.