Leather is the skin of animals: deer, cow, calf, sheep and goat were the main animals used, but others were sometimes added to this list.
Leather had to be processed to prevent it rotting; sheep, goat and calfskin was often simply part-rotted, de-haired and scraped clean of fat and flesh, then washed, dried and scraped repeatedly to make parchment or vellum for writing.
Leather for belts, straps, bags, sword scabbards, knife sheaths and other items was either tanned or tawed; tanning used the bark of oak or other trees which is full of the chemical tannin, giving the finished leather a bright reddish-brown finish and preserving it quite effectively. Tawing used alum, oil, eggyolks and salt in place of tannin to create white leather (but this was far less resistant to rotting).
All types of leather could be softened by covering it in warm dog manure or cold chicken droppings. All leather-working processes could also include the use of stale urine. The smell must have been obvious for a wide distance around the leather-working workshop.
Good quality leather goods were decorated in various ways: metal punches could emboss a repeat pattern, or metal tools could engrave decoration, or coloured silk stitches might be added to shoes or belts.
During the Middle Ages, leather was quite commonly worn, especially for belts and shoes.
Leather aprons over wool tunics.
A cordwainer was a person who made high quality shoes, boots, and products out of soft leather for wealthy people. There is a link below.
In the middle ages
men would wear a baggy shirt ang trouses made from a thin material and wemon would were a stright dress some made from leather.
Yes, they had gelatin in the Middle Ages. It seems they made it from antlers. Possibly later, they made it from bones.
The fall of Rome created the situation that made the middle ages.
They made armour