I've been doing a little research on my name "Gil de Lamadrid" These are just some ideas.. I'm not professional of any kind so please do you own research and correct me if I'm wrong before I confuse a thousand people..:)
As it has been stated in this forum, the Gil family seems to have changed their names over the years. There are Gil, Gill, Gil de Lamadrid, and many other Gil- with a different name altogether. All of these are apparently variants of the 'Gil' surname.
OK. some interesting info..
Old Norse - gil meaning ‘ravine’ or 'stream'.
Middle English - gil(l)ravine or stream
Punjabi - the word "Gill" is probably derived from 'Gil' meaning ‘moisture’ or 'stream/lake'
Gill is also an ancient Jat Clan which carry the surnamesGill, Gille and Gilles; where 'Gil' means stream/lake
We can see that from India to Europe, the word Gil has consistently meant 'a river or stream' in various languages.
My theory or wild guess is that we the 'Gil' family settled in Europe and at the time of the inquisition were forced to either leave or to take on the name of the city they lived in.
According to what I have read, a lot of the people in Spain who carry the name of a city like Madrid, Lamadrid, Sevilla, etc; were people who were targeted by the inquisition, most likely Jews, and they had to take on one of these names or face prosecution.
If this is the case I am surprised that they were allowed(or lucky enough) to keep the 'Gil' prefix, or family(clan)identifier, in their new given names.
So, according to theory I am a 'Gil' of Lamadrid(because my family had to take the name of the residing city of Lamadrid) Others are 'Gil' of(wherever) and some are still just Gil or Gill.
This would explain the numbers of 'Gil' family members who do not have roots in Spain but also carry the name 'Gil' unaltered.
I hope this was helpful in someway. Once again, let me make it clear that I don't know what I'm doing and am just presenting a 'possibility'. None of my statements have been analyzed. I'm just sharing information I came across today.