Who Is Bowser?

This one is for my one and only true love
Princess Peach
Peach, you're so cool
And with my star, we're gonna rule
Peach, understand
I'm gonna love you 'til the very end
Peaches, Peaches, Peaches, Peaches, Peaches
Peaches, Peaches, Peaches, Peaches, Peaches
I love you, oh
Peaches, Peaches, Peaches, Peaches, Peaches
Peaches, Peaches, Peaches, Peaches, Peaches
I love you, oh
Mario, Luigi, and a Donkey Kong too
A thousand troops of Koopas couldn't keep me from you
Princess Peach, at the end of the line
I'll make you mine, oh
Peaches, Peaches, Peaches, Peaches, Peaches
Peaches, Peaches, Peaches, Peaches, Peaches
I love you, oh
Peaches, Peaches, Peach, Peach

[@Eris1987]

There is a portrait in TTYD that might depict Bowser's Father.
Bowser has only 1 son and no daughters.
The Koopalings are not Bowser's children.
Bowser's original motives was purely conquest and he only later developed feelings for Peach.