On facebook today and somene mentioned how some folks spend an awful lot of time on long backstories for their PCs. I agree some folks spend an awful lot of time on them for no real benefit.
It's like people think a multi-page backstory is going to save them from blowing that last saving throw.
had a character who became emperor of his realm and his whole backstory
was "Bastard child of a nun and minor prince of The Empire next door". That was the whole backstory. It was presumptive, I don't think the DM or I had a clue there was an empire next door at the time, eventually there was one and my player invaded it with his army a couple times until a big chunk was taken over. The backstory never conflicted with play.
The interesting stuff about a character happens while playing the campaign. The backstory only needs to be a brief hook. Keep it short. Make sure it fits the campaign. Leave room to build onto the charater's story later.