The Sunni/shiite divide occurred over?

The sunnie and shiite divide occured because there was a debate about the rightful succession after the death of the prophet Muhammad. Basically there were multiple people who were "qualified" to take the place of Muhammad upon his death and it was between two people: one of which believed what the Sunni people believe and the other who believe what the Shiites believe.

Sorry if this doesn't make sense I know what I am trying to say it just isn't coming out quite how I want it to

yes it ended over 1,400 years ago.