Brief Lock History ~ Early Pin Tumbler
The earliest example of the modern pin tumbler lock was found in Egypt.
The lock consisted of a vertical wooden housing containing several loose wooden pegs of varying lengths which fit into holes bored in the top of a wooden bolt.
This prevented the bolt from being moved thereby locking the door.
An oblique slot in the bolt allowed access for a long wooden key with pegs of varying lengths located on one surface and corresponding to the pegs in the vertical housing.
Inserting the proper key into the bolt and lifting the lined pegs inside the housing, allowed the door to be opened.