A rare title for Lord of Minas Tirith, and by extension the realm of Gondor. The title is in fact only recorded on a single occasion, in reference to Steward Denethor, but in theory it might have applied to any of the rulers of the city dating back to its change of name to Minas Tirith, the 'Tower of Guard'. This occurred in III 2002, after Minas Ithil had fallen to the Nazgûl. Thus the first Lord of the Tower of Guard was the King of Gondor at that time, Eärnil II. Eärnil's heir Eärnur would be the last of the Kings, and after his time the Lords of the Tower of Guard were the Ruling Stewards down to the time of the War of the Ring and the restoration of the Kingship.

For a detailed genealogy and list of Ruling Stewards, who were Lords of the Tower of Guard through most of its history, see the entry for Ruling Steward.