First creation

The first Mosley baronetcy, of Rolleston, in the County of Stafford, was created in the Baronetage of England on 10 July 1640 for Edward Mosley, of Rolleston Hall, a grandson of Sir Nicholas Mosley of Hough End Hall (who acquired the Manor of Manchester in 1596 and was Lord Mayor of London in 1599), and nephew of the lawyer Sir Edward Mosley (the youngest son of Sir Nicholas and his first wife Marjorie, née Whitbroke). Sir Edward was a lawyer who had been knighted by King James I of England in 1614; appointed a justice of the peace and Attorney-General for the Duchy of Lancaster; and elected as a Member of Parliament for Preston in 1614, 1620–1622, and 1624–1625. It was Sir Edward who first acquired the properties of Rolleston Hall that became the family seat. Sir Edward (1569–1638) died unmarried and without issue, and his estates were inherited by his nephew—the Edward Mosley who was to become the 1st Baronet.

The 1st Baronet's father was Rowland Mosley (1558–1616), another son of the aforesaid Sir Nicholas and his wife Marjorie.

The second Baronet, also called Edward, sat as Member of Parliament for St Michael. The baronetcy became extinct on his death in 1665.

Second creation

The second Mosley baronetcy, of Rolleston, in the County of Stafford, was created in the Baronetage of Great Britain on 18 June 1720 for Oswald Mosley, a third cousin once removed of the second Baronet of the 1640 creation. The title became extinct on the death of the third Baronet in 1779.

Third creation

The third Mosley baronetcy, of Ancoats, in the County of Lancaster, was created in the Baronetage of Great Britain on 8 June 1781 for John Mosley, who was a second cousin of the second and third baronets of the 1720 creation.^{[lower-alpha 1]} His grandson, the second Baronet, represented several constituencies in the House of Commons. His grandson, the fourth Baronet, served as High Sheriff of Staffordshire in 1915.

The sixth Baronet, Sir Oswald Mosley, grandson of the fourth Baronet, gained notoriety as the founder of the British Union of Fascists. He married as his first wife Lady Cynthia Curzon, second daughter of George Curzon, 1st Marquess Curzon of Kedleston. Lady Cynthia and her two sisters were in special remainder to the barony of Ravensdale created for their father in 1911. After Lady Cynthia's early death in 1933, the sixth Baronet married, as his second wife, the Hon. Diana Mitford, former wife of the Hon. Bryan Guinness and one of the famous Mitford sisters.

In 1966, Mosley's son from his first marriage, author Nicholas Mosley, succeeded his mother's elder sister, Irene Curzon, 2nd Baroness Ravensdale, in the Ravensdale barony, but didn't use the title. On his father's death in 1980, he also inherited the baronetcy of Ancoats, and became the seventh Baronet. On his death in 2017, he was succeeded in both titles by his grandson, Daniel Mosley, who became the 4th Baron Ravensdale and the 8th Baronet.^{[lower-alpha 2]} He is an elected member of the House of Lords.

Tonman Mosley, 1st Baron Anslow, younger son of the third Baronet, was a politician. Max Mosley, second son in the second marriage of the sixth Baronet, was the long-serving President of the Fédération Internationale de l'Automobile.

The family seats were Rolleston Hall, near Rolleston on Dove, Staffordshire, and Ancoats Hall, near Manchester.

Arms

The arms of the 2nd Baronet are blazoned: Quarterly—1st and 4th, sable a chevron between three battle axes argent; 2nd and 3rd, or a fesse between three eagles displayed sable. Crest—An eagle displayed ermine. Motto—Mos legem regit.^[3]