“We’ll even call [our first son] Louis if you like. Louis le Premiere, how’s that for a King of England?!”
Henry II to his mistress, Alais (daughter of King Louis VII of France) in THE LION IN WINTER
Well, Lewis is usually a last name, and the trend of last names as first names is rather downmarket (in the US, too – “Jordan,” “Taylor”… no offense), plus it’s Welsh.
“Lewis” is originally a given name. It’s a family name only in the sense of “descendant of Lewis.”
Well, come on, use your head! Two Popes already took Lennon and McCartney’s names. And since Starkey is still living, that leaves Harrison’s name. It makes sense to me. 
There was a Beatle named Francis? 
Was he the drummer before Ringo?
Pope Francis, the first of his name, is two popes? Simultaneously all at once together?
He would have gone for three, simultaneously, all at once together, but, you know, didn’t want to push his luck.
As is Philip, directly imported by a Byzantine princess into the French royal house. And Louis is German, imported by the Carolingian Franks into France. So we have Greek name-Greek name-German name for the prince. None of which means anything of course.
The only stereotypical Anglo-Saxon names used with any frequency post-Conquest is Edward, mostly because the otherwise very franco-centric Henry III was fascinated with the cult of Edward the Confessor ( he also resurrected Edmund for his younger son ). Just luck of the draw - if Edward I’s eldest to survive toddler-hood had lived long enough to take the throne, it would have likely engendered a procession of kings named Alphonso. If Edward I’s eldest born ( John, died ~ age 5 ) had lived or Edward III had died young, England would have seen more than one King John and the later animus attached to the name would have probably been snuffed out.
From “Philippos”, “philos” + “hippos”, meaning friend or lover or horses.
Um, of horses.