By Gilbert Cruz
Updated November 19, 2004 at 05:00 AM EST

David Kertzer’s fascinating and thuddingly exhaustive book, featuring archived Vatican documents, lays out the largely untold story of the Roman Catholic Church’s attempt to sabotage the creation of a unified Italian state. Up until 1870, the Pope was essentially king of Rome and the surrounding Papal States. But after nationalists captured the city and declared it the capital of a new, secular, and united Italy, Pius IX and Leo XIII spent several decades threatening to move the Vatican to another country and conspiring with Catholic nations, such as France, seeking to overthrow the Italian king. Ultimately, Prisoner of the Vatican‘s compelling historical narrative manages to overcome Kertzer’s dry professorial writing.