How did Spain extend its power abroad and at home?

The Spanish had conquests and weapons to extend it power.

Explanation:

Why did Spain decline as a major European power?

Many different factors, including the decentralized political nature of Spain, inefficient taxation, a succession of weak kings, power struggles in the Spanish court and a tendency to focus on the American colonies instead of Spain's domestic economy, all contributed to the decline of the Habsburg rule of Spain.

Explanation:

i would think it's industries and hydroelectric power