During the first decade of the existence of the new Kingdom of Italy, the new state faced a number of challenges. There were still parts of the Italian peninsula that were not yet in the Kingdom, such as Venice and Rome. Austria still controlled Venice and there would be yet a third war of Italian independence in 1866 to liberate Venice.. Rome was still in the hands of the Pope with the protection of French troops. Emperor Napoleon III did not want to withdraw French troops without some plan of protection for the Pope because he depended on support at home in France from conservative Roman Catholic French voters. So he needed some reasonable agreement with the Kingdom of Italy for the protection of the Pope, if French troops left Rome. Then there was the constant changing of government leadership: Prime Minister after prime Minister, all with problems with the king who wanted to run the country by himself.  


Christopher Duggan,

A Concise History of Italy,

Cambridge University Press; 2 edition (January 20, 2014),

ISBN 0521747430