Before he was Silky Harris on The Alaskans, and before he was Beau Maverick on Maverick, and before he was Simon Templar in The Saint, and before he was Lord Brett Sinclair on The Persuaders, and before he was 007 in the James Bond films, Roger Moore was Sir Wilfred of Ivanhoe in the 39 episodes of the syndicated series Ivanhoe.
Ivanhoe was a joint production of Screen Gems Television and England's Sydney Box Productions. Plans were to sell the pilot to ABC so cast and crew headed to Los Angeles to film the pilot. But ABC did not bite so the remaining 38 episodes were filmed in England. Interestingly, the pilot had been shot in color but after ABC rejected it, it was televised in black and white, fitting for a syndicated show of the time.
As a series, Ivanhoe soon leaves Sir Walter Scott's novel in the dust. Wilfred (usually referred to as Ivanhoe) is soon stripped of his title and becomes a roving knight bringing justice to bad Prince John's England. He is aided by peasant leader/servant Gurth (Robert Brown) and, for a while, by Gurth's son Bart -- who is soon dropped from the series, only to remain in the opening where he blows a horn and yells "Ivanho-o-oe." Lady Rowena appears only in the pilot episode.
(Robert Brown and Moore remained friends and Moore arranged for Brown to play James Bond's M for his last two films; Brown continued in that role after Moore left the franchise.)
linked below is the pilot episode for the series, "Freeing the Serfs."