Eärnur is the only known Captain of Gondor, and so his dates are shown above, but in principle there may have been many such Captains through the history of that land, and thus through the entirety of the Third Age and beyond. It should be noted that neither of Eärnur's dates is absolutely certain. His date of birth appears only in draft texts in volume XII of The History of Middle-earth volume XII, and the fact that he was lost in Minas Morgul means that his exact date of death remains unknown.

Eärnur, the only known holder of the title, was descended from the House of Anárion. From later history, it seems that the Gondorians had a preference that leaders of their forces should be drawn from the ruling house (for example, both Boromir and Faramir, heirs to the Stewardship, held such roles). On purely practical grounds, however, it does seem unlikely that all of the captains across history would have been heirs to a ruling line.

Minas Tirith only gained that name during Eärnur's lifetime, with the capture of Minas Ithil by the Nazgûl. In Eärnur's youth, his home city would still have been known by its old name of Minas Anor. Even Minas Anor had not always been the chief city of Gondor, and during its early centuries, if a Captain of Gondor existed during that period, they would have been based at Osgiliath on Anduin.