Some of the powerful viceroys of Dushan's provinces speedily made themselves independent.
During the rule of Don Pedro de Toledo (one of the best viceroys) Naples became the centre of a Protestant movement which spread to the rest of Italy, but was ultimately crushed by the Inquisition.
It had been protected under the native kings by a system of dikes, which were added to under the earlier viceroys, but serious inundations in 1553 and 1580 flooded the city, and the latter suggested the relief of the highest lake, that of Zumpango, by a tunnel carrying its chief affluent into a tributary of the Panuco, and so to the Atlantic. This, however, was not then undertaken, and when mooted again in 1603 was opposed as certain to involve a heavy sacrifice of Indian life.
The extortions necessitated by these wars for the maintenance of armies and the incompetence of the viceroys brought Egypt at this time into a miserable condition; and the numerous political crises at Bagdad prevented for a time any serious measures being taken to improve it.
Casual excavations are mentioned under the Spanish viceroys, but regular exploration only began.