There are prophecies by catholic saints who said that the Muslims would invade into Europe and try to destroy the Vatican. 
It is the first and the only Mosque in Rome, located at the foot of the hill. It was erected in 1984-93, and designed by Paolo Portoghesi, Vittorio Gigliotti and Sami Monsawi. The mosque, that can hold up to 3000 people and is the largest in Europe, was financed by some 24 Arab countries. There is also a cultural center and library here.
The mosque requested and received permission from the Italian Gov't to erect a crescent moon that rises higher than the cross on the Vatican.
According to Zenit News Agency, In June 2003, the Islamic Cultural Center of Rome ousted the imam from the city's Great Mosque after he urged the faithful in a sermon to "destroy the enemies of Islam."
"Are we not to fear, during this period, that the Mohammedans will come again, working out their sinister schemes against the Latin Church?"...Venerable Holzhauser
Then he goes on to say that after the coming world war that "the empire of the Mohammedans will be broken up."
"I saw the Church of St. Peter: it had been destroyed but for the Sanctuary and the main Altar."-Venerable Emmerich
"Mary will extend the riegn of Christ over the heathens and Mohammedans and it will be a time of great joy when Mary, as Mistress and Queen of Hearts, is enthroned."-Venerable Mary of Agreda
"She (Our Lady) will extend the Kingdom of Christ over the idolators and Moslems, and there will come a glorious era in which Mary will be the ruler and Queen of human hearts."-St. Louis De Montfort
They all say the same things, that there will be a falling away from Christianity, the Catholic Church will be infiltrated and full of corruption. Christians will be persecuted and a great war will break out in Europe, in which the Muslims and others will invade and almost conquer Europe.
But, a Frenchman, descendant of royal blood will ally himself with a 'strict' pope and fight against the invaders and finally destory and convert them.
They say there will be extraordinary disturbances in nature and a three days darkness.
After that will be a short time of peace and then the Antichrist will come.
Interesting stuff.
Even Belloc in one of his books mentions the Muslims rising to power again.