The key as a Symbol
For thousands of years, people have wanted to protect their worldly goods. The first documented lock dates back to the third millennium BC. The first safety cylinder lock was constructed by its inventor Linus Yale jun. in New York in 1865 and its operating principle has lost nothing of its validity. During this long history, the key also became a symbol and entered language and the arts. For instance, Paul the Apostle is often depicted with a key in his hand. And the word 'key' signals truly important occurrences and situations – from the 'key moment' in our life to the formal 'key ceremony'.