President Umbra Prince is one of the three presidents of Panem created by Anon....
He was born to normal Capitol parents the year that the 2nd Rebellion ended (I.e the year that Catching Fire took place) He has a sister called Lucy who is married to Glacier Frost.
He became President by chance, and runs Panem Fairly. He is married to Iris Prince and has a daughter. Iris went missing when she tried out one of Umbra's inventions, something that he blames himself for. He plans to take over the whole world, so that he can get Iris back.
So he is going slightly insane, and he is looked after by his personal bodyguard.