Random worldbuilding from the Unfinished Book:
The nomad peoples of the plains and mountaineous regions have a traditional protocol for making peace between long-warring peoples - the exchange of orphans. Though the various tribes and peoples all have their own languages, cultures and ways, they all know of the tradition. It's not considered something that came from any specific people, but something as natural, obvious, and universal as knowing where the sun rises, and that you ride a horse by sitting on its back. It's simply What People Obviously Do.
If and when two clans who have been enemies manage to negotiate peace between them, both sides choose a child - or several, if we're talking about entire tribes with a history of war with each other - and exchange them as emissaries. The chosen children aren't necessarily required to be orphans, but generally tend to be, as no parent would willingly volunteer to part with a child they want to raise. There's a specific ideal age window for the chosen children, old enough to know their own peoples' customs, but still young and malleable to adapt to a different culture and learn to speak their language as fluently as a native.
From there on, standing awkwardly between the two cultures, with one foot in their own old tribe's ways and customs and one foot firmly within the new one's culture, isn't just their fate but their duty in life. Their task is to learn of the new clan and teach them something of their own old clan's ways, and generally showing them that these Others whom they were taught to regard as an enemy are truly just people, too. While becoming a translator and a diplomat is a heavy burden to put on a kid who's usually somewhere between the ages of seven and twelve at the time of the exchange, they do enjoy a rise in standing in life - going from a child in their old clan whom nobody really wanted, into someone of a revered status.
From there on, these Exchanged Children are brought along to every negotiation between the clan leaders - not only to work as literal translators of the languages spoken, but the cultural ones as well. If one clan leader says something that offends the other one, there are two youths in the room who can negotiate from somewhat-mutual ground to determine whether the insult was intended, and work together to explain both leaders where the cultural difference is between them in this. If both of them can agree that one of the cultures considers dogs to be revered and dignified creatures, and the other one doesn't think as highly of them, they can explain to both chiefs how saying that someone has "the heart of a dog" could be intended as a compliment and read as an insult.
In the Empire, the nomad custom has been appropriated into a legal way for feuding noble families (and later, remarkably wealthy merchant houses who have not yet bought their way into nobility but want to copy their customs anyhow) to make peace with each other. However, their way of seeing the custom has turned it into "give up your least-favourite child to be your enemy's assigned punching bag, but in return you get one of theirs as a consolation prize", essentially making them court-mandated hostages. Everyone agrees that the idea of ensuring that both sides have a child as a hostage is brutal and savage, and even a baroness who would happily yeet her unwanted son into the hands of a woman she absolutely hates, and would happily brutalise whatever kid she's traded in return, will act disgusted of how savage this custom must be in The Plains, where no court of law will supervise what the nomads do with them.
Meanwhile, the nomad peoples themselves would be absolutely horrified to learn how badly these imperialist, invading barbarians have perverted a sacred custom.