I've never been obsessively interested in geneology, but I have done enough online research to learn a little bit about my family history. The name Pettigrew means "small growth" in French, which sounds a lot like a wart to me. Not exactly complimentary, but it beats being called Pettipoo and Pettipants (two of my unwanted nicknames when I was in grade school).
You might think that I was French, but not so. It seems that my family line goes back to the days of William the Conqueror, according to one family member who researched the matter. Now, Willie was from France, but he became a resident of the U.K. (not yet united in any way) by leading the Norman Conquest.
A lot of French folks also moved to England during the aftermath of the Catholic persecution of the French Huguenots in France. One of the infamous incidents related to that persecution was known as the St. Bartholomew's Day Massacre. That incident happened in 1572, so it clearly followed the Norman Conquest by about 500 years or more.
It should hardly be a surprise that the Pettigrew clan has leaned towards Protestantism ever since, or that my research has shown that the Pettigrew family members who moved to Ireland to moved to the northern part of that country. One ancestral place in Ireland was known as Crilly House. There were also Pettigrews in Scotland, especially around Lanarkshire. From Scotland and Ireland, Pettigrews seem to have migrated to the United States, Australia and other English-speaking countries.
I've never actually visited those countries, and at this late stage in my life, it seems unlikely that I ever will. But it's interesting stuff to learn, nevertheless.