Oath of Eorl
Also agreed was whenever help was needed, the two kingdoms would aid each other. The signal that help was needed was the Red Arrow, a symbol of danger. For faster communication between the two allies, the warning beacons of Gondor were used. These beacons were placed on seven hills along the northern ridge of the White Mountains.
 The Oath
The Oath was first sworn in T.A. 2510 by Cirion, the twelfth Ruling Steward of Gondor, and by Eorl, King of the Éothéod (later first King of Rohan) following the Battle of the Field of Celebrant. The Oath stated that the province of Calenardhon would be forever of Rohan, established its borders, and an alliance between the kingdoms. The two rulers swore their oaths on the Halifirien hill at the site of the Tomb of Elendil.
Eorl spoke his oath in his own language:
Hear now all peoples who bow not to the Shadow in the East, by the gift of the Lord of Mundberg we will come to dwell in the land that he names Calenardhon, and therefore I vow in my own name and on behalf of the Éothéod of the North that between us and the Great People of the West there shall be friendship for ever: their enemies shall be our enemies, their need shall be our need, and whatsoever evil, or threat, or assault may come upon them we will aid them to the utmost end of our strength. This vow shall descend to my heirs, all such as may come after me in our new land, and let them keep it in faith unbroken, lest the Shadow fall upon them and they become accursed.
Vanda sina termaruva Elenna-nóreo alcar enyalien ar Elendil Vorondo voronwë. Nai tiruvantes i hárar mahalmassen mi Númen ar i Eru i or ilyë mahalmar eä tennoio.
Which in Westron translates to "This oath shall stand in memory of the glory of the Land of the Star, and of the faith of Elendil the Faithful, in the keeping of those who sit upon the thrones of the West and of the One who is above all thrones for ever."
Eru's name was very rarely invoked in oaths, and indeed had not been since the time of the Last Alliance. Among people of Numenorean descent, it was held that only the King could call upon Eru, but Cirion had that authority as Steward and regent for the King.
 History of the Oath
In T.A. 2710 King Déor asked the help of Steward Egalmoth to drive off the Dunlendings from the occupied Ring of Isengard, but a renewed war against the Orcs prevented the Steward from fulfilling the Oath.
During the rule of Beren, both nations where overwhelmed; Gondor by the Corsairs of Umbar and Rohan by the Dunlendings, and couldn't help each other. After the Long Winter however, as the Rohirrim started to repel the invaders, Gondor afforded sending help from both west and east of the White Mountains to assist them.
Gondor sent great help to King Folcwine who reconquered the west-march from the Dunlendings. In T.A. 2885, when Ithilien was invaded in great strength, Folcwine sent many men, led by his twin prince sons, to Gondor. With their aid Steward Túrin II won a victory at the Crossings of Poros, though the princes Fastred and Folcred were slain.
During the War of the Ring, the Red Arrow was brought to King Théoden of Rohan by a messenger of Gondor while Minas Tirith was besieged by Sauron, and Théoden rode out with the Muster of Rohan to the Battle of the Pelennor Fields.
- ↑ J.R.R. Tolkien, "The Rivers and Beacon-hills of Gondor" (edited by Carl F. Hostetter), in Vinyar Tengwar, Number 42, July 2001, p. 20
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "Cirion and Eorl and the Friendship of Gondor and Rohan"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Peoples of Middle-earth, "The Heirs of Elendil"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The Battles of the Fords of Isen"
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix A, "The Númenorean Kings", "Gondor and the Heirs of Anárion", "The Stewards"
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix A, "The House of Eorl"
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix A, "The House of Eorl", "The Kings of the Mark"