Who is Edward
The great Gilbart and Edge "Edward" Debacle
Warning: This Content May Contain Plot Spoliers. Please be aware of this before continuing.
Who is Edward in Final Fantasy IV?
It depends upon whom you ask. If you ask a Japanese FF4 gamer they'll tell you it's Edge, the Eblanian Ninja. If you ask an English-Speaking FF4 gamer they'll tell you that, why it's Edward the Bard-Prince of Damcyan of course. And of course the latter would be incorrect, but not due to any fault of their own.
According to the SSH, the name of the character Edge is actually "Edward Geraldine", and it is implied that "Edge" (which is used as his name in all in-game dialog) is actually a clever contraction of the first two letters of his first and last names, as well as a reference to his penchant for utilizing very sharp objects. The SSH also tells us that the Bard-Prince of Damcyan is "Gilbart Chris von Muir", moreover he's actually Gilbart VII to be precise. This is because all of the crown princes (and thus Kings) of Damcyan have been named "Gilbart" since the ruling line came to power. Gilbart is used as his name in all in-game dialog in the Japanese and I do believe non-English translations of the game.
So why then is he called "Edward" in every English translation? Well it's a lingering defect from the first English translation known as Final Fantasy II for the SNES. Actually it's more of Final Fantasy IV legend now just like the infamous "Spoony Bard" line (also about Gilbart / Edward oddly).
In Final Fantasy II SNES there is one main reason why the name is not Gilbart; it's a seven letters word. The character width for names in the original game was only six characters, so the name couldn't fit in the space allowed in English. However that doesn't really explain the choice of Edward as the replacement. If Ted Woolsey and his staff had an SSH the likely alternate might have been "Chris" no? Maybe that didn't sound right so they picked something else? Did they not have an SSH, called the guys over at Square Japan and asked, we need another name for the Prince in our Final Fantasy IV translation, and thinking they were speaking about Edge (Edge and Gilbart are both princes) the other end of the line said "We'll his name is also Edward?" we just don't know.
So while I cannot explain the choice of Edward for Gilbart, at least you know now that Edge is Edward and Edward is Gilbart, sense make?
While we're on the subject, other less annoying name changes were: Kain's name is actually supposed to be spelled in roman letters with a "C" instead of a "K" (which is why it's rendered that way on this site), and Tellah's name doesn't have an "h". Also almost every playable character has a surname and some even have middle names, so you FanFic authors should probably look them up in the character section unless you want to specifically make them up. The only ones that don't are Rydia (known simply as "Rydia of Mist", Tella(h) (officially "Tella the Sage" but he could be "Tellah of Kaipo" —which is where he and Anna are supposedly living, Palom and Porom (known again as "Palom and Porom of Mysidia"), and Anna (which of course is "Anna von Muir" after the elopement but her maiden name would be that as Tellah).