I learned this story from my father who in turn learned from either his grandfather or great grandfather. My grandfather was born in 1910 so I guess his grandfather was born in early to mid 1800s. My dad great grandfather was not French, so the Monge brothers of this story must have left France in late 1700s or early 1800s.
The story goes like this:
Four Monge brothers left France to come to the Americas. Two of the brothers and their descents settled in Central America and the Caribbean. The other two went to Peru.
Of the two that went to Peru, one stayed in Lima and the other one went a bit south to Ica. The latter went to Huancavelica via Castrovirreyna route. This is my side of the Monge family. The descendents of the brother that stayed in Lima either remained in Lima or traveled north to Piura.
I went to school with a Monge from the Lima branch. My dad and this kid's dad became friends. One day, after more that a few glasses of wine they started to tell family stories and what not. The guy from Lima also had learned of the four brothers story from his grandfather.
This story was told to my dad before Luis Alberto Monge was elected President of Costa Rica and Yolandita Monge became famous. So, I guess there must be some truth to the story since there are Monges in Central America, Caribbean and two different regions of Peru as the story tells.