When was the first statutory patent issued?
The first statutory patent system is generally regarded to be the Venetian Patent Statute of 1450. Patents were systematically granted in Venice as of 1450, where they issued a decree by which new and inventive devices had to be communicated to the Republic in order to obtain legal protection against potential infringers. The period of protection was 10 years. These were mostly in the field of glass making. As Venetians emigrated, they sought similar patent protection in their new homes. This led to the diffusion of patent systems to other countries.
The picture is of James Puckle's 1718 "autocannon", one of the first inventions required to provide a specification for a patent.