However, he had to rethink his career, when, after expecting to take over from Nicholson, he realised that Jonjo O'Neill was lined up for the position instead.
Now he is getting the just reward for his hard work in establishing himself at his Barbury Castle Stables, previously occupied by the late Mikey Heaton-Ellis.
King said: "If you work hard enough at it, and are patient, it is surprising what you can achieve.
"It doesn't happen overnight, but if you keep your head down it should come right in the end."
Tomorrow, Bear On Board may give his trainer yet another surprise and justify all that effort by landing the world's most famous race.