On the death of his elder brother Colonel Thomas Frederick Mackenzie Humberston in 1783, Mackenzie became the last male heir of the attainted Earls of Seaforth.
Thomas Jefferson | Thomas Edison | Thomas | Thomas Hardy | Thomas Mann | Frederick the Great | Thomas Aquinas | Clarence Thomas | Thomas Gainsborough | Dylan Thomas | Thomas Pynchon | St. Thomas | Frederick | Saint Thomas, U.S. Virgin Islands | Thomas Carlyle | Frederick II | Frederick II, Holy Roman Emperor | Thomas the Tank Engine | Thomas Moore | Thomas Cromwell | Thomas Becket | Frederick Russell Burnham | Frederick Roberts, 1st Earl Roberts | Thomas the Apostle | Thomas Merton | William Lyon Mackenzie King | Frederick Law Olmsted | Thomas Tallis | Thomas Paine | Frederick I, Holy Roman Emperor |