Egyptian Locks

• Following the invention of the pin-tumbler lock, the Egyptians evolved the design to incorporate pegs that would be lifted by slots in a key. These locks were around two feet in length with wooden keys of a similar length.
  
  

Metal Locks

• The Roman Empire further developed lock making by creating the first metal locks, which included obstructions only the correct key could pass through to open the door. The Roman Empire also developed the first u-shaped padlock; the Chinese developed a padlock independently of the Romans.
  
  

Colonial America

• The American settlers created a primitive door lock that included an outdoor "key." Doors were still locked with wooden bars or bolts that were lifted by pulling a piece of rope from the outside of the building, allowing the door to be opened. This was to ensure visitors felt welcome from the moment of arrival.
  
  

Robert Barron

• In 1778, Englishman Robert Barron changed the art of making locks forever with his invention of a double-acting tumbler lock, which sparked the beginning of the modern era of the locksmith. Barron's lock required the correct key to raise what were essentially two levers to the correct height for the lock to open a door.
  
  

Joseph Bramah

• Joseph Bramah's safety lock debuted in 1784 and is still the model for most door locks in use today. Bramah's lock includes small metal tubes with narrow slots cut in the end that must be opened for the door lock to be opened.
  
  

Yale

• Linus Yale patented an improved version of the Egyptian pin-tumbler lock in 1848, calling his invention the compact cylinder lock. The Yale lock is still in popular use as a door lock for domestic residences.