1) Arquebusier 1) Combat occupation 2) Obsolete occupation 
The harquebusier was the most common form of cavalry found throughout Western Europe during the early and mid 17th century. Early harquebusiers were characterised by the use of a form of carbine, called a `harquebus`. In England, harquebusier was the technical name for this type of cavalry, though in everyday usage they were usually simply calle.....
(from the article `tactics`) ...In order to compensate for these disadvantages and build staying power, 16th-century units such as the famous Spanish tercio were made up of ...