There was an answer someone gave on here to a question I cannot remember (I think it was one of those old poll-type questions). I have used so many different keywords in this reddit's search and google and I have come up with nothing.
The war and/or battle/siege in question was started when (I'm fuzzy on the names and title) one noble fellow plays a prank on another which ends up with a bucket of excrement on the prank victim's head. When the prank victim goes to the King (who maybe is his father?) for restribution and gets none delcares war and besieges the castle, or city, or whatever it was.
As I said, many of the details are very fuzzy, so I am very sorry for possibly mangling that piece of history, or remembering a highly fictionalized version of something.
The only thing I can think of with this description is the sons of the Conqueror.
On Henry:
"Orderic places him with his two older brothers in a house in Laigle (south-central Normandy) in late 1077 or early 1078 where the siblings has a serious falling out. William Rufus and Henry, "deeming their strength equal to that of their brother Robert," infuriated him by directing fetid water (urine?) down upon from the upper gallery, shaming him in the presence of his numerous followers. Orderic describes William and Henry on this occasion as having been casting dice "as was the custom of soldiers" before setting about to moisten Robert. Since Henry cannot have been more than eight or nine years old at the time, one is inclined to doubt that he actually took part in the event that, although memorable, occurred several decades before Orderic wrote." - C. Warren Hollister, Henry I
Which David expands on Roberts action afterwards: "...he rushed in upon the offenders, and a wild scuffle ensued, which was only terminated by the timely arrival of the King, who upon hearing the clamor, came in haste from his lodgings and put a stop to the quarrel by his royal presence. Robert, however, remained sullen and offended; and that night accompanied by his intimates, he withdrew secretly from the royal forces and departed. Riding straight for Rouen, he made the rash venture of attempting to seize the castle by surprise attack, an action which seems almost incredible, except on the hypothesis that a conspiracy with wide ramifications was already under way." - Charles Wendell David - Robert Curthose,Duke of Normandy
No historian though and I hope someone flair'ed comes in for you. this is the only thing I could think of though. The episode itself doesn't have a name I believe so that's probably why it doesn't show up in any searches.
William the Conqueror, father Robert Curthose, eldest son William Rufus, second eldest Henry, youngest
Hope that's helpful.