Dr. Catherine "Cathy" Gale Initially, was one of several rotating partners who worked with Steed (the others being medical man Dr Martin King and nightclub singer Venus Smith). By the third season, however, she was Steed's only partner.
Gale was born 5 October 1932. She was an anthropologist who married a farmer in Africa and there learned to hunt, fight and take care of herself. When her husband was killed, Gale returned to London to earn a Ph.D. in anthropology. She was the curator of a museum when she first encountered John Steed and agreed to work alongside him from 1962-1964. She is engaged in charities.
JOHN STEED AND CATHY GALE
The relationship between Steed and Gale was marked by sexual tension of a type absent from later partners, plus Gale and Steed also had a rocky working relationship, with Gale not always appreciative of Steed's methods nor his habit of "volunteering" her for missions. Still, the two appear to have become quite close as the episode "The Golden Eggs" has her actually living in Steed's apartment as she searches for a new home of her own (the reason for her displacement is not revealed). In keeping with The Avengers' policy of avoiding direct references to romance between the two leads, however, it's quickly stated that Steed is actually sleeping at a nearby hotel.