- The costs of many wars rapidly emptied the Spanish treasury.
- Profits from the Americas caused growing inflation in Spain.
He governed with strict personal control over councils and secretariats and thus showed his inability to distinguish the important from the trivial and the inability to decide quickly on important issues. An example of an absolutist monarch, his government was exercised on the basis of a highly centralized administration, marked by rigorous taxation, and died in the El Escorial palace, one of the most important monuments in Spain erected during his government, near Madrid. On the religious plane, he resorted to the Inquisition against Protestantism in his domain.