In ancient Athens, slaves were always examined by torture, and for this reason their evidence was apparently considered more valuable than that of freemen. A free Athenian could not be examined by this method, but torture may have been used occasionally in executing criminals. Under the Roman Republic only slaves could be legally tortured, and as a general rule, they could not be tortured to establish the guilt of their master. Under the Roman Empire, however, by the order of the emperor, torture was frequently inflicted even on freemen to obtain evidence of the crime of laesa majestas ("injured majesty," or crime against a sovereign power). The statesman Cicero and other enlightened Romans condemned the use of torture.
Until the 13th century torture was apparently not sanctioned by the canon law of the Christian church; about that time, however, the Roman treason law began to be adapted to heresy as crimen laesae majestatis Divinae ("crime of injury to Divine majesty"). Soon after the Inquisition was instituted, Pope Innocent IV, influenced by the revival of Roman law, issued a decree (in 1252) that called on civil magistrates to have persons accused of heresy tortured to elicit confessions against themselves and others. This was probably the earliest instance of ecclesiastical sanction of this mode of examination.
During the Middle Ages the influence of the Roman Catholic Church contributed to the adoption of torture by civil tribunals. The Italian municipalities adopted torture early,