The Colonna and the Orsini: a feud, a papal bull and two weddings
What the record shows clearly
In short: The feud existed. A papal bull called Pax Romana, issued by Julius II in 1511, formally ended it. It came back, and in 1571 the two heads of house married nieces of the same pope.
Other parts of the story often told about the Colonna and the Orsini — the street fighting, the towers, the alternating loyalties — go beyond this page.
1511, and what a bull can and cannot do
Pax Romana is the interesting document precisely because it did not work. A pope formally ended a feud between two families and the feud resurfaced, which tells you something about the limits of the office in Rome at that date and something about the families. It is worth knowing that the instrument failed.
1571, twice
The year turns up in this family’s file two ways. The heads of both houses married nieces of Pope Sixtus V — a settlement by marriage after the settlement by bull had not held. And Marcantonio II Colonna commanded the papal fleet at the Battle of Lepanto, which is the event painted across the vault of the Great Hall.
Those are two separate facts that share a year.
Do the Orsini still exist?
This page focuses on the Colonna, whose present is documented in detail — Don Prospero, born 1956, heads the main line; Prince Marcantonio Colonna di Paliano, born 1948, is Prince and Duke of Paliano; the family’s papal office was abolished in 2018 after 504 years. The Orsini are not covered in the same detail.
Where a page answers either way, it is worth seeing what it cites.
Why the question gets asked at all
Because one half of the pair is visibly still here. You can buy a ticket, walk up a staircase with an 1849 cannonball in it, and stand in a room belonging to people whose name has been on this street since the 1200s. That is unusual enough that the natural next thought is: and the others? The family page has the Colonna side of it in full.
If you take one thing from the pair, take the failure of the bull. Two families were ordered to stop and did not; a generation later they married the same pope’s nieces instead. Marriage settled what an instruction could not.
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Frequently asked questions
How did the Colonna–Orsini feud end?
Formally, by the papal bull Pax Romana, issued by Pope Julius II in 1511. It resurfaced anyway, and in 1571 the heads of both houses married nieces of Pope Sixtus V.
Does the Orsini family still exist today?
This site focuses on the Colonna, whose present is documented here in detail; the Orsini are not covered in the same way.
What was Pax Romana?
A papal bull issued by Pope Julius II in 1511 that formally ended the feud between the Colonna and the Orsini. The feud resurfaced afterwards.