The only recorded historical event to take place during Eärendil's reign came three years after his accession, when Elrond's daughter Arwen was born in the north. No one in Gondor at that time, of course, could have known how significant that event would be: nearly three thousand years later, Arwen was to wed Aragorn, a distant descendant of Eärendil's ancestor Elendil, and become Queen of his realm.
Eärendil ruled Gondor for eighty-six years, and was succeeded by his son, Anardil.
Notes
1
The date of Eärendil's birth appears only in The History of Middle-earth volume XII, The Peoples of Middle-earth. It cannot therefore be considered completely reliable.