Baptist churches began with Jesus Christ, and the “slur” of anabaptists came very early on before the Catholic cult formed in the 4th century.
Stephen, heretical bishop of Rome, attacked the bishops (pastors) of true churches in Asia Minor, Cappadocia, Galatia, and Cilicia, and applied to them the epithets of Rebaptizers and Anabaptists, A.D. 253.