Title of a book I read years ago? It was about a trader in the Aztec empire, any ideas anyone?

I'm not sure at what point in the main character's life it started, but it ranged right through to the invasion of the spaniards and told of how the Aztec king ordered all of the gold thrown into the sea so that the spaniards couldn't have it. I loved this book, but never took note of the title and I read hundreds of books a year, (I'm disabled so I have lots of time). So, does it strike a bell with anyone? Thanks.