Steve Henderson was a friend of Diana Paxson, who (according to oral tradition) was the reason for the backyard party at Berkeley in 1966. Diana was joining the Peace Corps, and her friends threw a going-away party for her that featured a medieval theme. The man who would later become Sir Steven attended the party along with his roommate (Count Stefan de Lorraine) and "a friend...from down the hall" (Duke Henrik ap Havn).
Sir Steven was King of the West in the early 1970s. Among his many other accomplishments, he wrote several popular SCAdian filk songs, such as "A Grazing Mace", that are staples of campfire gatherings even today.
Henderson was also known for his co-founding of DunDraCon, a west coast convention for role playing gamers.
The link from this article goes to Steven's personal home page, which is still active as of this writing. A memorial page is being created for him in the West Kingdom.