Today there was a "TIL" post on the front page stating that at the Siege of Weinsberg in 1138 (?) he stated the "castle wives" could leave the castle with whatever they could carry on their backs. Eschewing gold or other valuables, the women left the castle carrying their husbands, sons, and other loved ones thrown across their shoulders. He let them pass, stating he would honor his word. Is any of this remotely true?
Alright, so the source for this story is the Chronica regia Coloniensis (the "Royal Chronicle of Cologne"), also called the Annales Colonsiensis maximi. This chronicle was written sometime around 1175 (the original manuscripts only go up to this year, even though it was later ammended to cover events up to 1202) in the Archbishopry of Cologne and covers the deeds of the Roman emperors (as well as their East Roman and Frankish/German successors) and German and Frankish kings.
For the year 1140 (not 1138 as the TIL post claims), the annals give us this entry:
A. D. 1140. rex urbem Welponis ducis Baioariorum, Winesberg dictam, obsedit et in deditionem accepit, matronis ac ceteris feminis ibi repertis hac regali liberalitate licentia concessa, ut quaeque humeris valerent deportarent. Quae tam fidei maritorum quam sospitati ceterorum consulentes, obmissa suppellectili descendebant viros humeris portantes. Duci vero Friderico ne talia fierent contradicente, rex favens subdolositati feminarum dixit, regium verbum non decere immutare. (Annales Colonsienses maximi, MGH SS, Book 17, p. 759, 17-27)
This would translate roughly to (I couldn't find an English translation on the fly and my Latin is more than rusty (plus this is medieval Latin), so I'm translating a German translation):
In the year of the Lord 1140, the King laid siege to a city of Duke Welf of Bavaria, which was called Weinsberg, and accepted their surrender, whereas he allowed, out of his royal generosity, the wives and other women who were present to take with them whatever they could carry on their shoulders. Considering the loyalty to their husbands aswell as the wellbeing of the others, they [the wives and other women] abandoned their household goods and descended, carrying the men on their shoulders. When Duke Friedrich protested that they should not be doing this, the King said, benevolent towards the deceit of the women, that it would not be appropriate to change the word of a King.
So, as we can see this is pretty much 1:1 the story the TIL post described (with the added bonus of Duke Friedrich II., who was the brother of the king, challenging the women and being rebuked by the King).
Now, there are no other sources alluding to the event, but the source was written only 35 years after the event, so it isn't really disputed (as in: we can't disprove it and it's not outlandish enough to outright rebuke it). So as far as we can tell from today, this episode really happened. It also sparked a sort of "traveling tale", giving rise to a number of stories in Germany where similar ruses are supposed to have happened with clever wives saving their husbands (such as during the sieges of Gelsterburg or Weidelburg castle). But this story is the only one that has a source behind it to back it up.