A major impetus for this movement was the invasion of Italy by the German Emperor Friedrich Barbarossa. Northern Italy's city-states banded together in opposition to form the "Lombard League". The Emperor's goal in invading Italy was to force the Pope to recognize him as the supreme authority in the Empire (he would even set up his own anti-pope). Any honest observer could see that this was an absurd position. The Holy Roman Empire had been formed entirely by Papal authority in the first place when Charlemagne was crowned in 800 AD by Pope St Leo III. However, the wars between the Guelphs and the Ghibellines would trouble northern Italy for a long time as other factors reinforced the opposition of each side.
What became known as the Neo-Guelph movement began to take shape later in the 19th Century, when nationalistic fervor was on the rise and Italy seemed to once again be on a collision course between temporal and spiritual forces. Much of this movement was sparked by the massive book Il primato morale e civile degli Italiani by Vincenzo Gioberti, a priest who had at one time been the chaplain to King Carlo Alberto of Sardinia. His book looked back at the entire history of Italian greatness and rejected the view of the radical liberals, such as Mazzini and Garibaldi, that a united Italy would have to be at odds with the established religion. On the contrary, Gioberti took the view that it was the Papacy alone which could best accomplish the national unity which the pan-Italian nationalists most desired.
The Neo-Guelphs were mostly moderate, educated people, considered to be at least somewhat liberal by the standards of the day, who supported Italian unification, but only through traditional authorities and under the sovereignty of His Holiness the Pope. The basic goals of the Neo-Guelphs called for some progressive reforms in the Italian states, but their purpose was to support rather than undermine the legitimate rulers. They called for an Italian federation which would be ruled by a college of the traditional princes under the overall reign of the Pope, who would act as the primary source of unity for the new country. They called for representative assemblies in the various states, but whose sole purpose was to advise the monarch rather than to govern. Each state would be able to maintain their local autonomy and unique differences with the Pope acting as a sort of president, however not over a republic, but a "federation of consultative monarchies".
As historians, such as E.E.Y. Hales, have noted, this basic idea was not a completely new idea. For a long time it would have been considered simply common sense. During the history of Italy, since even before the fall of the Roman Empire, the Church had been the dominant force, the most important factor, the greatest source of art and culture and the best example of Italian achievement. It therefore seemed natural that any move towards Italian unity would have to under the general guidance and leadership of the Church. In a country so entirely Catholic as Italy, who else but the Pope would be entitled to the place of honor in any coalition of governments?
However, we all know that this did not come about. Through the unnatural alliances of the House of Savoia with the French and the radical republicans Italy was united by conquest rather than Christian brotherhood. Blessed Pope Pio Nono seemed the ideal man to follow the Neo-Guelph model, being both a patriotic Italian and a firm traditionalist. However, he was not given the chance. Still, the Guelph and Neo-Guelph movements serve as an important historical lesson for our modern times as well. The nature of the world itself has not changed, nor has the nature of Christianity. All Christians must still ask themselves the question: to whom is your ultimate allegiance, to your local political leader, or to the leader of your Church?