When his eldest brother, Henry Beaufort, 3rd Duke of Somerset, was killed fighting for Lancaster in 1464 at the Battle of Hexham, the next brother, Edmund, succeeded to the Dukedom, and John became "Marquess of Dorset" and "Earl of Dorset", courtesy titles granted to the Beaufort heir-apparent or heir-presumptive.
Dorset | Charles Cornwallis, 1st Marquess Cornwallis | Weymouth, Dorset | Robert Gascoyne-Cecil, 3rd Marquess of Salisbury | Marquess | Francis Rawdon-Hastings, 1st Marquess of Hastings | Richard Wellesley, 1st Marquess Wellesley | Marquess of Bute | Wills Hill, 1st Marquess of Downshire | River Stour, Dorset | James Broun-Ramsay, 1st Marquess of Dalhousie | David Cecil, 6th Marquess of Exeter | Robert Grosvenor, 1st Marquess of Westminster | Henry Paget, 1st Marquess of Anglesey | Frederick Hervey, 8th Marquess of Bristol | Frederick Hamilton-Temple-Blackwood, 1st Marquess of Dufferin and Ava | Victor Hervey, 6th Marquess of Bristol | Robert Wynn Carrington, 1st Marquess of Lincolnshire | Marquess of Rockingham | Marquess of Lansdowne | marquess | John Neville, 1st Marquess of Montagu | Freeman Freeman-Thomas, 1st Marquess of Willingdon | Christchurch, Dorset | Thomas Sackville, 1st Earl of Dorset | Richard Sackville, 3rd Earl of Dorset | Paul Marquess | Marquess of Milford Haven | Marquess of Anglesey | Marquess of Ailsa |