Pepin I of Aquitaine

However, this is not the end of the story, as in 831 AD, Louis would face yet another rebellion of his three elder sons against him, and this time it would not be resolved as easily.

The trouble began with Pepin, who apparently was still feeling somewhat peeved that his share of the realms had been diminished for his baby brother Charles and had been summoned to his father's court at Aachen to answer for his perceived lack of loyalty.

It is really not clear what happened at this meeting, but Pepin was somewhat poorly received by his father, though how he could expect a cheerful embrace after having rebelled against him two years before is hard to understand.

He was so poorly received, in fact, that Pepin of Aquitaine found himself languishing in a jail cell in Trier over the winter of 831 AD.

Louis the Pious, to add insult to injury, forced the nobles of Aquitaine to swear allegiance to a new king, Charles, the youngest son of the emperor.

It all looks a bit grim for Pepin, but daringly, he seems to have flown the coop.

It's not clear how, but in the dead of night around New Year's Eve 831 AD, he managed to get out of his cell.

I am picturing bedsheets out the window kind of thing, and he was gone.