Thus matters remained in 1867-70, the Pope relying on the support of French bayonets to coerce his own subjects.

Clearly this was a state of things which could not continue.

The first great shock must always bring down a political edifice which rests not on its own foundations, but on external buttresses.

These were suddenly withdrawn by the war of 1870.
Early in August, Napoleon ordered all his troops to leave the Papal States; and the downfall of his power a month later absolved Victor Emmanuel from the claims of gratitude which he still felt towards his ally of 1859.
At once the forward wing of the Italian national party took action in a way that either forced, or more probably encouraged, Victor Emmanuel's Government to step in under the pretext of preventing the creation of a Roman Republic.

The King invited Pius IX.