The History of the Popes During the Last Four Centuries
by Leopold von Ranke (1795-1886)
Published by G.Bell & Sons Ltd., London, 1906
and
The Pope and the Council
by Johann Joseph Ignaz von Dollinger (1799-1890)
Published by Roberts Brothers, Boston, 1870
These books cover a variety of topics such as:
Theory of Ecclesiastical Policy
Conflicts of Opinions
Latter Times of Sixtus V
Election and Character of Clement VIII
Jesuit Programme for the Council
Modern Civilisation and Constitutionalism Condemned
Personal Attitude of the Popes
The "Curia"
Trials for Witchcraft
... and lots more!
Stop by and spend some time with these more-than-a-century old books. It'll be worth your while.