Elros was the first King of Númenor in J.R.R. Tolkien’s legendarium.
Elros and his twin brother Elrond were the sons of Eärendil and Elwing. At the end of the First Age, they were given a choice between the fates of Elves and Men. Elros chose the fate of Men, while Elrond chose to remain counted among the Elves.
After the War of Wrath, the island kingdom of Númenor was established for the Edain, the Men who had aided the Elves. Elros became its first king under the name Tar-Minyatur and ruled for many years.
Elros is easy to confuse with later Númenórean rulers. Elendil founded the realms in exile of Arnor and Gondor after Númenor’s destruction, while Isildur was Elendil’s son and heir.