The Russians, Chinese, Turkish and East Indian, used ornate metal padlocks which untilised all kinds of intircate designs. The keyhole was often concealed. Europe Variations Sometime around the late 1500's, a lever tumbler was added to the warded locks to make them more effective. More elaborate warding was the only way to make the locks more secure. Keyhole were concealed by shutters or other devices.
Nurenberg metalworkers become well known for their locks and keys.
Later on the French locksmiths produced beautiful work. The tumbler, a lever that falls into a slot in the bolt, preventing any movement, until picked up by the key to the height of the slot. This had to be done for eack of the two tumblers at varying heights, then the key would slide the bolt. This inovation is still the basis of all lever locks. In 1784, Joseph Bramah, displayed in his London store a lock with a sign offering 200 guineas to anyone who could pick it.