Intel did not dominate X86-silicon out of the starting-blocks.
Oh really? In case the other laughing (and well-deserved) responses aren't educating you, allow me to spell it out for you:
Intel invented the x86 market, and supplied 100% of all IBM PC systems, as well as all clones that soon followed from Compaq and others. It wasn't until the 386 generation that AMD reverse-engineered Intel's design and sold a copycat product (or was it the 286 generation? Getting old, memory foggy).
The tale of how Intel and Microsoft inked deals with IBM that allowed them to sell to other suppliers has gone down in technology lore as enabling the creation of the entire PC industry as we know it. To be a follower of this industry and not be aware of this history is truly mind-boggling...