Vidumavi
From Tolkien Gateway
The daughter of Vidugavia, King of Rhovanion. She wedded Valacar, the royal ambassador of Gondor, and together they had a son, Vinitharya, who would become known as Eldacar. Vidumavi's was the first non-Númenórean blood to enter the Royal House of Gondor, a fact that would lead to the civil war of the Kin-strife.