Formerly known as (renamed characters)

[Tzigone]

There are quite a few of these, but I thought I'd try to create a list - feel free to correct errors

Had to start with the Flash family
Barry was first Barrence, then Bartholomew
Wally was first Walter, then Wallace
Iris' dad was first T.H., then Ira (I don't count William, as he's a very different character)
Wally's dad was first Bob, then Rudy (but I can't think when each name was established and if it was a pre-to-post COIE change, I'd count that as a different character like his dad, since he was very much reshaped)


Moving on

Alfred Beagle became Alfred Pennyworth
Hippolyte to Hippolyta
Steve Howard Trevor or Steve Rockwell Trevor
Mary Kent to Martha Kent

[Güicho]

You seem to be mixing up two separate ideas (or sequence of events) when you say "first":
Eg:

You say Barry was first Barrence, then Bartholomew
Yet to the readers Barry was first Barry (Showcase #4 1956), the names Barrance etc were revealed later.

That is different idea (or sequence of events) from your next example:

Alfred who was first known as Beagle (Detective #96 1945 ) and then was later changed to Alfred Pennyworth Batman #216, November 1969

[Tzigone]

You seem to be mixing up two separate ideas when you say "first":

You say Barry was first Barrence, then Bartholomew
To the readers Barry was first Barry, the names Barrance etc were revealed later

I'm don't think I'm mixing things up (well, about this). Yes, Barry is often a separate name, but with the Barrence reveal, it becomes a nickname, and probably wasn't intended to be perceived as an entirely different given name, as Bartholomew was. Been a while since I read that story, but that's what I thought anyway. Much like a character may be Ted and be revealed as Theodore or Edward. And, now let's add Ted Kord to the list. (Or Jack can be Jackson or Jonathan or so forth, and now I'm wondering if we have one of those).

Alfred who was first known as Beagle (Detective #96 1945 ) and then was later changed to Alfred Pennyworth Batman #216, November 1969

Yes.

[Güicho]

You seem to be mixing up two separate ideas (or sequence of events) when you say "first":
Eg:

Barry was first Barrence, then Bartholomew

Alfred Beagle became Alfred Pennyworth

Yes they are both "name changes" they have that in common.
Yet you don't see how those two changes are different? Two separate ideas ( sequence of events)?
Might seems a relevant distinction.
Yet you're presenting them (or compiling them as the same), could be conveying misleading information;