What level of power did the Swedish Empire have under Gustavus Adolphus, under his military and diplomatic influence?
Swedish Empire:  The beginning of the Empire is usually taken as the reign of Gustavus Adolphus, who ascended the throne in 1611, and the end as the loss of territories in 1721 following the Great Northern War. Great power:  Great powers characteristically possess military and economic strength, as well as diplomatic and soft power influence, which may cause middle or small powers to consider the great powers' opinions before taking actions of their own.
great power