Earliest visual representation of the crucified Jesus

Thanks to Myrto Theocharous for pointing me to this piece by Larry Hurtado, whose site I’m now linking under ‘Sites You Should Visit’. He makes the following point, but you should read the whole post to get all of them:

The “Staurogram” (the combination of the Greek letters tau and rho) did not derive from the chi-rho.  We have instances of the Christian use of the tau-rho considerably earlier than any instances of the chi-rho. These earliest uses of the tau-rho are in Christian manuscripts palaeographically dated ca. 200-250 CE.