When Elendil and his people escaped the Downfall of Númenor, they were driven across the Great Sea in nine ships. Seven of those nine ships each bore one of the palantíri, and these seven ships carried the symbol of a five-pointed star.¹ Also aboard these vessels was a seedling of the White Tree of Númenor, descended from the White Tree Telperion in Valinor, that Isildur had rescued from destruction. In Middle-earth, Elendil took the White Tree and the seven stars and made them his banner, surmounted by the crown of the High King, all in white on a black field.²

As the royal banner of the Dúnedain, the Tree and Stars flew over the royal cities of Gondor for more than two thousand years, until the last King of Gondor was lost and the Ruling Stewards came to power (the flag of the Stewards was plain white). As the emblem of Elendil, the Tree and Stars would presumably also have been used in the North-kingdom of Arnor, but if so, there are no accounts of its use in the North until the time of Aragorn Elessar at the end of the Third Age.

In Rivendell, Arwen Evenstar made a banner for Aragorn that carried the ancient royal symbols, including a crown made from mithril and gold, which was carried to him by the Dúnedain. The standard was first unfurled when Aragorn bound the Dead to his cause on the Hill of Erech, and he carried the banner with him as he captured a Corsair fleet at Pelargir. When that fleet sailed to the Battle of the Pelennor Fields, the flag of the Tree and Stars flew from its mast. Aragorn then concealed the banner for a time, but he carried the Tree and Stars proudly in challenge of Sauron to the battle before the Gates of Mordor, and afterwards it flew over the Citadel of Minas Tirith to proclaim the return of Gondor's true King.

The arrangement of stars on the banner of the Tree and Stars is a little unclear. Its description in Appendix A to The Lord of the Rings says that the Tree was 'beneath' the Stars, but elsewhere (in The Return of the King V 6, The Battle of the Pelennor Fields) it is said that the seven Stars were 'about' the Tree.

In art and film, the stars tend to be shown in an arc or semicircle above the crown of the Tree, a layout that perhaps follows the design of the (otherwise unrelated) seven stars of Durin on the West-gate of Moria. In fact, Tolkien's own rendering of the Tree and Stars (on a design for a dust-jacket of The Return of the King) is rather different, with the stars being arranged in a symmetrical pattern among the branches of the flowering Tree.