The first known horcrux was made by Herpo the Foul. The only other known creator of a horcrux was Lord Voldemort. He is very likely the only wizard who has successfully created more than one horcrux.

Horcruxes were originally concieved as a singular act. It was unknown for many centuries what the attempted creation of multiple horcruxes would result in, as nobody thought it was possible to accomplish such an act.