When that prince was deposed by the French in 1799 the Capponi family followed him into exile at Vienna, where they remained until he exchanged his rights to the grand duchy for a German principality (1803).

Besides knowing Jeffrey he made the acquaintance of many prominent statesmen and men of letters, including Lord John Russell, the duke of Bedford, Dugald Stewart, and Ugo Foscolo.

But the collapse of the rising of 1821 and the imprisonment of Confalonieri made Capponi despair of achieving anything by revolution, and he devoted himself to the economic development of Tuscany and to study.

[4] At his beautiful villa of Varramista he collected materials for a history of the Church; his work was interrupted by family troubles and by progressive vision loss.

When the grand duke Leopold II decided in 1848 to grant his people a constitution, Capponi was made a member of the commission to draw it up, and he eventually became prime minister.

During his short tenure of office he conducted foreign affairs with great skill, and made every effort to save the Italian situation after the defeat of Charles Albert on the Mincio.

He knew nearly all the most interesting people in Italy, besides many distinguished foreigners: Giuseppe Giusti, the poet, Alessandro Manzoni, the novelist, Niccolò Tommaseo, Richard Cobden, A von Reumont, the historian, were among those whom he entertained at his palace or his villas, and many were the struggling students and revolutionists to whom he gave assistance.

[2] As a historian his reputation rests on his Storia della Repubblica di Firenze (Florence, 1875); it was the first comprehensive Italian book on the subject based on documents and written in a modern critical spirit, and if the chapters on the early history of the city are now obsolete in view of recent discoveries, yet, as a whole, it remains a standard work.