Atlantan English

Due to internationality of the first Familiae, original official language of the Atlantis was Latin. Despite that, most citizens taught their children their language of origin. As a result, everyone was at least bilingual which helped when the further waves of migrants came to the Atlantis.
After the Congress of Vienna Atlantan ambassador to Britain started lobbying for a change of official language to English. The Society agreed during Rules-Review in 1825. While they kept many traditional terms in Latin and still taught it alongside English in schools, even the most official documents were republished in the translation. Most citizens transitioned fairly quickly to English while keeping the tradition of teaching the original language at home.
Some families even anglicised their names (Pemme> Pym, Ride> Reid, Percer> Pierce, Coulefils>Coulson, Fureur>Fury, Montagne> Hill etc.). Most however decided to keep their original ones as part of their heritage (Odinson, Stark, T'Cha, Potts).