He devoted twenty years to the composition of his great work, the Storia civile del regno di Napoli (History of the Kingdom of Naples), ultimately published in 1723.

[3] In his account of the rise and progress of the Neapolitan laws and government, he warmly espoused the side of the civil power in its conflicts with the Roman Catholic hierarchy.

In Vienna the favour of the Emperor Charles VI and of many leading personages at the Austrian court obtained for him a pension and other facilities for the prosecution of his historical studies.

[4] The post of consulting lawyer to the republic, in which he might have continued the type of service that Fra Paolo Sarpi had exemplified in previous centuries, was offered to him, as well as that of professor of public law in Padua.

He wandered under an assumed name for three months through Modena, Milan and Turin, he at last reached Geneva, where he enjoyed the friendship of the most distinguished citizens, and was on excellent terms with the great publishing firms.

In the fortress of Turin he remained imprisoned for the last twelve years of his life, although part of his time was spent in composing a defence of the Sardinian interests as opposed to those of the papacy.