The Colonna and the Orsini: a feud, a papal bull and two weddings
What this page is working from
Three sentences, and I would rather show you the size of the evidence than dress it up. 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.
Everything else you have read about the Colonna and the Orsini — the street fighting, the towers, the alternating loyalties — may well be accurate. It is not sourced on this site, so it is not stated on this site as though it were.
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 the only instrument this site can point to and 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 facts that share a year. I am not going to join them into a narrative, because nothing I have read joins them and a coincidence of dates is the easiest thing in the world to write a false paragraph about.
Do the Orsini still exist?
People type that, and land here, and deserve a straight answer about why they are not getting one. The material behind this site documents the Colonna’s present 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. It carries nothing comparable about the Orsini.
So I do not know, and I am not going to assemble an answer out of half-memories about a family whose building I do not stand in every week. If a page tells you confidently either way, ask it where it checked.
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 cannot answer that from the sources behind it. It documents the Colonna’s present in detail and carries nothing comparable on the Orsini, so it does not guess.
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.