Most of my knowledge of the conquest of Mexico comes from Bernal Diaz's account, which while one of the best books I've ever read, has some debatable historicity of it's account. One question that's nagged me recently is the source of Aztec's gold, since I'm sure at least official records document large shipments of gold melted down from Aztec gold early on, but most of the precious metals brought back from the New World after was silver. So where did they get it from?

We know Aztecs were a tributary empire, so perhaps their vassals were supplying them with a lot of gold over a lot of time. But were their known vassals ever known to be big possessors of gold, does this hold up? I've heard they were also relatively newcomers to the region, so perhaps they migrated with a lot of gold in their possession as well.

Another indicator, if Bernal's account is even anywhere near true, is how freely they lavished the Spanish with golden gifts, so either they recognized the importance of these new arrivals, and/or had so much gold laying around that these gifts were deemed appropriate for them (a fair amount of time ion Bernals account is spent discussing precisely what the gifts were, the "quality" of the gold, and the disagreements over how it was split up). I suppose none of these impressions are mutually exclusive, so it could have just been all of the above contributing to the nature of how seemingly gold laden the Aztec's were. It's struck me how much they seemed to have but yet not a lot was brought back after.

That said, the Spanish who entered Mexico City for the first time must have been completely awestruck. (before they tore the city down brick by brick in the ensuing fight)