I know what you're thinking.
You don't remember ever seeing Ivanhoe. I know I didn't. However, it was a British-American co-production, produced in England for what would become ITC, and distributed here in the US by Screen Gems, and was meant to air here as well as in the UK.
Ivanhoe, the first TV series to adapt Sir Walter Scott's classic tale (there've been two others since), lasted just 1 season of 39 episodes. Star Roger Moore returned to Hollywood to make movies before returning to the UK in 1962 to begin work on The Saint, and, of course, we know the rest of his story, don't we?
ATV, the forerunner to ITC, was doing a series of shows aimed at younger viewers that doubled as teaching tools regarding legendary heroes such as Robin Hood in the 50's, before moving on to science fiction (Gerry Anderson's super-marionation line) and, for adults, spies and variety shows in the 60's and early 70's.
In memory of Moore, who passed away at 89, here's the episode, "Counterfeit":