The second son of KingBrego of Rohan. His elder brother Baldor had been lost while attempting to pass the Paths of the Dead, and so Aldor succeeded his father to become the third King of Rohan. He was just twenty-six years old when he came to the throne, and his reign of seventy-five years was the longest in the annals of the Mark. On account of his great age - he reached his one hundred and second year before he died - he is often referred to as Aldor the Old.
Aldor was the founder of a golden age in Rohan's history. In his time, the Rohirrim increased greatly in numbers, and he succeeded in driving all the Dunlendings from his realm. Aldor had many children, of which the three eldest were daughters. It was his fourth child, Fréa, who succeeded him as King, but due to Aldor's long life, Fréa had to wait until he was himself seventy-five years old before he became Lord of the Mark.
In common with all the rulers of Rohan, Aldor had a name deriving from an Old English word meaning 'ruler' or 'chief'. The source of Aldor's name, ealdor, had another meaning too: 'elder' or 'parent'. This was surely not a coincidence, as the choice of name is peculiarly suitable for the longest-living and longest-ruling of all Rohan'sKings.