The invention of the wheellock in Europe can be placed at about 1500. There is a vocal group of scholars who believe Leonardo da Vinci was the inventor. Drawings made by Leonardo of a wheellock mechanism date (depending on the authority) from either the mid-1490s or the first decade of the 16th century. However, a drawing from a book of German inventions (dated 1505) and a 1507 reference to the purchase of a wheellock in Austria may indicate the inventor was an unknown German mechanic instead.