The transformation of hide into leather as basic clothing material is one of the first deliberate activities of mankind. Ancient historical sources, among others, the Talmud and the Bible preserved references concerning leather. Tanning is basically used for preserving leather from rot: in its possibly most ancient form, the raw hide, when drying, was exposed to fireplace smoke. More sophisticated tanning procedures are described in detail. Evidences on leather tanning in Hungary are collected. Tanning can be considered one of the earliest industrial activities of man. -- AATA