  We put forward the conjecture that all CP violating phenomena may have a
common origin. In order to illustrate our idea, we present a minimal model
where CP is spontaneously broken at a high energy scale, through the phase in
the vacuum expectation value of a complex scalar singlet. This single phase is
the origin of both low energy CP violation in the quark and leptonic sectors,
as well as leptogenesis. We also show that in this framework the strong CP
problem may be solved in a simple way through the introduction of a Z_4
symmetry which allows for the implementation of the Nelson-Barr mechanism.
