Vivien Merchant has a prominent role in this movie, but doesn't say a word. Critic Pauline Kael suggested sarcastically that she'd probably refused to say her lines, as the dialogue in the movie was unspeakably bad. That turned out to be the truth.
Second theatrical movie of Sir Ian McKellen (Roger). A Touch of Love (1969) was his debut, having been released sooner.
A 3/4-sized replica of the White Horse in Berkshire was recreated on the slopes of Knockma Hill in County Galway. It was designed and cut 18 inches deep, 280 feet long, 60 feet at its widest, and filled with about 17 tons of plaster. The Berkshire White Horse, which dates from before the English and Viking battles, was the scene of King Alfred's encounter with the Viking invaders.
When first announced by MGM in 1964, this was going to be titled "A King is Born".