Eärnil laid his claim as being a direct descendant of King Telumehtar Umbardacil. His claim was also greatly bolstered by the popularity he had gained as the victorious general who saved Gondor from the Wainriders after winning the southern theatre of the war. Steward Pelendur who was temporarily ruling Gondor as serving as arbiter of succession, intervened in favour of Gondor’s victorious general who would rule as Eärnil II.
The Last Heir of Anárion:
During the Battle of Fornost, Eärnil II’s heir Eärnur led Gondor’s forces to victory over the Witch-king of Angmar, who was actually the Lord of the Nazgûl. Although Eärnur wished to fight him, Eärnur’s horse was terrified and fled the battle against his wishes. By the time, he mastered his horse and returned the Witch-king had fled. Glorfindel the Elf then prophesied to him that it was better that he not fight the Lord of the Nazgûl because “never by the hand of man shall he fall”.
Eärnur later ascended to the throne, ruling from Minas Anor (“Tower of the Sun”). During this time, the Ringwraiths captured the city of Minas Ithil (“Tower of the Moon”), renaming it Minas Morgul (“Tower of Dark Sorcery”) and taking it as their lair. Minas Anor was renamed Minas Tirith (Tower of Guard) as a result. The Lord of the Nazgûl repeatedly sent messengers to Minas Tirith challenging Eärnur to single combat, taunting him that he had fled out of cowardice from facing him during the Battle of Fornost. Eventually, King Eärnur was overcome by wrath and rode with a small company of knights to Minas Morgul, to accept the challenge. They were never heard from again; and so ended the Line of Anárion.
The Stewards of Gondor:
A long line of hereditary Stewards governed the realm after the disappearance of Eärnur, son of Eärnil, since there was no proof that the last king was dead, and no claimant had enough support to be accepted as his successor. The line of Anárion was held to have failed, and Gondor was not willing to risk to another Kin-strife, which would surely have destroyed it. Whenever there was a new Steward, he would swear an oath to yield rule of Gondor back to the King, in essence only an heir of Isildur, if he should ever return. In Gondor, there was no one who could claim descent from Isildur in direct line, and the northern line of Arnor had effectively disappeared, so this oath was not considered seriously. The line of Stewards ruled as Kings, without having the title. During the War of the Ring, the ruling Steward of Gondor was Denethor II, and his two sons were Boromir and younger Faramir- the latter being the last Ruling Steward of Gondor.
Cirion and Eorl:
In TA 2510 when Steward Cirion ruled over Gondor, the nation faced one of its greatest perils: an Easterling tribe named the Balchoth invaded Gondor with mass force. Gondor’s army marched to fight the Balchoth but were cut off from Minas Tirith and pushed back in the direction of the Limlight.