Common Sign Language

Common Sign Language aka CSL is a relatively well-known language throughout the Hexarchy, readily recongized though not considered a high spoken language.  It greatly helps facilitate communication with the CSL community in the Hexarchy, as it isn't an uncommon thing for children to be born deaf or incapable of speaking.
With the advent of CSL, jobs within the Hexarchy became more accessible for members of the community. No longer stuck assisting family members or just highly patient bosses, CSL speakers were able to go into other jobs. The Hexarchy Royals started learning CSL to communicate with members of staff, even advisors, who speak through CSL.
It can still be difficult for CSL speakers to communicate. The language is rarely a person's first language, and it can prove frustrating that so few can actually communicate with them. Even still, with CSL becoming more and more commonly spoken, people are able to at least recognize people who do speak CSL can and do understand them, whether it be because they can hear or because they can lipread, and that they are more than willing to hold conversations as long as the other person is patient and willing to learn a little.

Geographical Distribution

It is considered one of the major secondary languages throughout the Hexarchy.

Several people who have been born deaf or without a voice have reached very high rank. One such person is Ximena Airborne, who worked as the Royal Archivist of Illary. Being unable to speak never stopped her from pursuing her dreams of working for the archives and the sharp witted and sassy young land quickly became the Royal Archivist at the age of twenty-three.
Another is none other than the Queen of Rushiv, Esfir Orlvo. Completely deaf from birth, there was the rather funny incident where her lack of hearing led her to completely miss that the young man who had approached her was the prince of her country. The prince realized she couldn't hear and used a spell to translate her hand signs so he could understand her. She called him a cheater, which made him laugh and the rest was history.