Aragorn (disguised as Thorongil) serves in Rohan and Gondor
Event Type: General
Age: 3rd Age - The Stewards
Years: 2957 ~ 2980
2957—80 Aragorn undertakes his great journeys and errantries. As Thorongil he serves in disguise both Thengel of Rohan and Ecthelion II of Gondor.
The Return of the King, LoTR Appendix B, The Tale of Years: The Third Age
Ecthelion II. […] Aragorn of the North serves as a soldier in his forces.
The Peoples of Middle-Earth, HoME Vol 12, Part 1, Ch 7, The Heirs of Elendil: The Ruling Stewards of Gondor
[Aragorn’s] ways were hard and long, and he became somewhat grim to look upon, unless he chanced to smile; and yet he seemed to Men worthy of honour, as a king that is in exile, when he did not hide his true shape. For he went in many guises, and won renown under many names. He rode in the host of the Rohirrim, and fought for the Lord of Gondor by land and by sea…
The Return of the King, LoTR Appendix A, Annals of the Kings and Rulers: Here Follows a Part of The Tale of Aragorn and Arwen
Ecthelion II […] encouraged all men of worth from near or far to enter his service, and to those who proved trustworthy he gave rank and reward. In much that he did he had the aid and advice of a great captain whom he loved above all. Thorongil men called him in Gondor, the Eagle of the Star, for he was swift and keen-eyed, and wore a silver star upon his cloak; but no one knew his true name nor in what land he was born. He came to Ecthelion from Rohan, where he had served the King Thengel, but he was not one of the Rohirrim. He was a great leader of men, by land or by sea, but he departed into the shadows whence he came, before the days of Ecthelion were ended.
Thorongil often counselled Ecthelion that the strength of the rebels in Umbar was a great peril to Gondor, and a threat to the fiefs of the south that would prove deadly, if Sauron moved to open war. At last he got leave of the Steward and gathered a small fleet, and he came to Umbar unlooked-for by night, and there burned a great part of the ships of the Corsairs. He himself overthrew the Captain of the Haven in battle upon the quays, and then he withdrew his fleet with small loss. But when they came back to Pelargir, to men's grief and wonder, he would not return to Minas Tirith, where great honour awaited him.
He sent a message of farewell to Ecthelion, saying: "Other tasks now call me, lord, and much time and many perils must pass, ere I come again to Gondor, if that be my fate." Though none could guess what those tasks might be, nor what summons he had received, it was known whither he went. For he took boat and crossed over Anduin, and there he said farewell to his companions and went on alone; and when he was last seen his face was towards the Mountains of Shadow.
There was dismay in the City at the departure of Thorongil, and to all men it seemed a great loss, unless it were to Denethor, the son of Ecthelion […]
Indeed [Denethor] was as like to Thorongil as to one of nearest kin, and yet was ever placed second to the stranger in the hearts of men and the esteem of his father. At the time many thought that Thorongil had departed before his rival became his master, though indeed Thorongil had never himself vied with Denethor, nor held himself higher than the servant of his father. And in one matter only were their counsels to the Steward at variance: Thorongil often warned Ecthelion not to put trust in Saruman the White in Isengard, but to welcome rather Gandalf the Grey. But there was little love between Denethor and Gandalf; and after the days of Ecthelion there was less welcome for the Grey Pilgrim in Minas Tirith. Therefore later, when all was made clear, many believed that Denethor, who was subtle in mind and looked further and deeper than other men of his day, had discovered who this stranger Thorongil in truth was, and suspected that he and Mithrandir designed to supplant him.
The Return of the King, LoTR Appendix A, Annals of the Kings and Rulers: Gondor and the Heirs of Anárion: The Stewards