"Later locks were so beautifully fashioned that the artist obscured the mechanical intention."
F. J. Butter, Locks and Builders 'Hardware
The Egyptians, and possibly other ancient peoples around the same time, invented the first mechanical locks some 4,000 years ago. The locks were a development of the simple wooden crossbeam that slides horizontally across the back of a door to bar entry. To hold the beam, or bolt, in place, a set of movable pins were located on the back of the door which dropped by gravity into recipient holes on the bolt as it moved into place. To unlock the door from the outside, a wooden key with matching pegs or prongs was inserted through a hole; the key raised the pins above the bolt, allowing it to be pulled back by a handle. Such keys could be up to 2 feet (0.6 m) long.
The introduction of metal locks around a thousand years ago provided smaller, stronger, and more precise locking mechanisms. "Wards," solid obstructions within the lock to counteract tampering, were introduced by the Romans. Portable "travel" locks, or padlocks, were particularly useful to merchants on the trade routes of Europe and Asia.
In Renaissance Europe the locksmith became a master craftsman. Bespoke ornamental locks were commissioned by the rich as a symbol of taste as well as prudence. Since that time, the age-old and continuous battle between locksmith and lock picker has led to many ingenious variations.
