Fréaláf recaptured Edoras in a surprise attack and slew Wulf and ousted most of the Dunlendings. Fréaláf then became King. During Fréaláf's reign, Saruman came to Isengard, which had recently been regained control of, and settled down. At that time the Rohirrim gained greatly from his knowledge and wisdom.
References: Unfinished Tales, Lord of the Rings,
Tolkien Quiz Book
Fréaláf, son of Hilde (who was the sister of the
previous king, Helm
Hammerhand), was succeeded by his son, Brytta.