Final answer:
Aphrodite fell in love with the mortal Anchises because Zeus, eager to teach her a lesson for making gods fall in love with mortals, caused it. Their union resulted in the birth of the hero Aeneas.
Step-by-step explanation:
The goddess Aphrodite fell in love with Anchises due to the machinations of Zeus. In Greek mythology, it was often the case that gods would interfere in the lives of mortals and other gods. According to legend, Zeus decided to make Aphrodite fall in love with the mortal Anchises as a form of retribution; Aphrodite had been causing other gods to fall in love with mortals, so Zeus decided she should experience the same fate.
As for Anchises, he was a shepherd and prince from the Dardania near Troy. The union between Aphrodite and Anchises led to the birth of Aeneas, who would later become a hero of the Trojan War and the mythical progenitor of the Romans. This act of Zeus highlights the intricate relationships and disputes among the deities in Greek mythology.