In 1571 he was raised to the Peerage by the title of Baron Burleigh. He was soon afterwards appointed Lord High Treasurer, and the great distinction of the Garter was bestowed upon him.
But while his public life was thus brilliant, his heart was bowed down by domestic affliction. His first wife had lived but a few years, and after her death he married Mildred, daughter of Sir Anthony Cooke and elder sister of Anne Cooke, afterwards Lady Bacon.
These sisters were remarkable for their beauty, their accomplishments, and their learning. They were well skilled in music, could converse in many foreign tongues, and in their knowledge of Latin and Greek were equal to some of the most famous scholars of the day. Both these fair and charming women not only obtained but succeeded in keeping the strong love of their husbands.
After a married life of forty-three years, the loss of the wife he had so fondly loved rendered Lord Burleigh a broken-hearted man. His health gave way under the excess of his affliction, and, for the first time during his long and arduous career, he felt himself unable to perform the duties of his office.
He became changed in many ways. The brightness and cheerfulness of his temper left him. He grew silent and melancholy, and from the sad hour when she, who had been the angel in his house, was taken from him, he never regained that sunny hopefulness of disposition that in happier days had been one of his peculiar characteristics.
He entreated the Queen to allow him to resign, for he desired now to spend the remainder of his days in quiet and retirement; but Elizabeth, well aware that his abilities were as brilliant as ever, was unwilling to part with her most trusted counsellor.
He yielded to the Royal command, and from this time laboured if possible more assiduously than ever, giving himself neither rest nor relaxation. Notwithstanding such prodigious exertions, and the acute sufferings he endured from attacks of gout, his life was prolonged beyond the usual age of man.
His last memorable public act was endeavouring to give peace to his country, when reasonable terms might have been obtained from Spain.
These terms, though considered reasonable by Burleigh, were violently opposed by the Earl of Essex; who, having gained some reputation by the sword, was unwilling to favour peace.