Well, probably not one of the oldest professions in the world as The Worshipful Company of Farriers based in London only dates back to 1356 when it was first formed as a ‘fellowship’. Their records can only trace the nailing on of shoes to horses feet to about 200 years BC from the migratory Eurasian tribes.
The Roman Army was supported by cavalry and pack horses all of which had nailed on iron shoes. The soldiers who did this were considered as highly skilled and classified as ‘immunes’. These specialist soldiers were excused from heavier fatigue duties and kept away from combat as much as possible.
When we used to look after our own horses we had them shod by a local farrier who was fifth or sixth generation to maintain the tradition. The family tradition apparently started in World War I when a teenager in the family proudly told his Dad he was going to volunteer for the army. His dad raised merry hell and refused to allow him to join up. The lad was only a farm labourer with no special skills and so he would have been sent straight to the front line as cannon fodder.
What his Dad told him to do was to train and qualify as a farrier and then volunteer. That way he would be regarded as a modern day ‘immune’ and be kept away from the front line while he maintained the feet of the countless cavalry and pack horses used by the British army to support the war effort. He survived the war and the family tradition is still going strong nearly 100 years later.