The capital city of the Aztec Empire, Tenochtitlan had approximately 60 calpullis. When the Spanish colonizers overran the city in 1519, they referred to the calpullis as barrios, since at the time the word had about the same meaning in Spain.
Tenochtitlan, the Aztec Empire's capital, was divided into approximately 60 calpullis. When the Spanish conquistadors took over the city in 1519, they called these calpullis barrios, as the term at that time had a comparable meaning in Spain.