Answer:
As far as we know, Flan was invented by the Romans who were the first in recorded history to experiment cooking with eggs. We don't know when it was first made but there is a recipe for it in an ancient cookbook from the late 4th or early 5th century A.D. It was then brought to Spain and Portugal, whose Conquistadors brought it to the new world. Because it is a simple dessert of eggs, milk, and sugar it was cheap make and quickly adopted by the natives. Today various versions are found in Latin America, Brazil, Mexico, and the Philippines.