Goldwine was King of Rohan of the the first line that
ended with Helm Hammerhand, as he was the son of Fréawine
and the father of Déor. Goldwine ruled during the beginnings of
the Troubled Times for Rohan which culminated
with the overunning of the Kingdom during Helm's reign.
References: Lord of the
Rings, Appendix A, II The House of Eorl,
Genealogical info - p.1105