Roman Slave Collar (4th Century AD) and is on display at the Museo Nazionale Romano–Terme di Diocleziano in Rome. These collars were used by slave owners on slaves who had attempted to escape. When the slave in question possessed a skillset worth more than just killing them or selling them to the mines, the collar was used. Once it was placed around the neck, the iron was melted back together so removal was almost impossible. As can be seen by the rough manufacturing process, it was designed to be extremely painfull, rubbing against the skin leaving horrible scarring after a few years. The next level above this was body branding (like a steer), often on the forehead or both shoulders. The tag on the collar reads: "I have run away; hold me. When you have brought me back to my master Zoninus, you will receive a gold coin (aureus)." #drthehistories