1691: Lithuanian was Unofficial in the Polish-Lithuanian Commonwealth Aug 1, 2019
The Polish-Lithuanian Commonwealth had at least 5 official languages, but none was Lithuanian. Instead however, two contemporaneously dead languages—Latin and Hebrew—were official, as well as the now-dead Ruthenian, along with German and Polish. This is because those were the languages used for legal purposes, since almost all the nobility were Polish, and some laws and scientific materials were written in Latin. Jews often had their own laws and scholarship, for which they wrote in Hebrew, even though they spoke Yiddish normally. The official recognition of German and Ruthenian was mostly for the sake of foreign relations, though there were more Ruthenian speakers than Lithuanian speakers at some points. In fact, by some standards there was more recognition of Armenian than Lithuanian, despite there being only a small population.