In the former Roman frontier city of Mogontiacum (modern-day Mainz), archaeologists have unearthed a sprawling industrial complex identified as the Imperial Bureau of Military-Cavalry Harnesses. The excavation revealed a dedicated workshop for the mass production of standardized iron buckles and decorative phalerae used to equip the auxiliary cavalry units guarding the Rhenish Limes.
The discovery is significant for its inclusion of hardened iron templates—standardized molds used by smiths to ensure every harness component was interchangeable. This level of Roman military logistics demonstrates a precursor to modern assembly-line manufacturing, where the equipment of thousands of horses could be maintained and repaired using parts manufactured to a strict imperial specification.