Yes. Hence the term "lingua franca".

You could say it was like some kind of “lingua franca”.

There was a German King of Great Britain that largely communicated with his ministers in French.

Lingua Franca never heard of her

Umm, well, yea. That's history for you.

Some interesting résidues of French domination: one of the 2 work languages of the UN Secretariat with English, the 5 continental rings of the Olympic symbol (America is one), the coordinated universal time UTC acronym.