In school, one of our teachers was also a priest, and he told us that his job once required him to travel to the (former) Soviet Union.
His Russian colleague did not speak German, and he did not speak Russian. Latin was the only language in which they could communicate, and the first question by the Russian priest was:
Primo Levi managed to use Latin to communicate with a Polish priest with whom he didn't have any other language in common.
> After World War II the Italian writer and Auschwitz survivor Primo Levi was walking back to Italy from Poland. Tired and starving, he met a priest, who spoke neither French, or German, or Italian. Ubi est mensa pauperorum? Levi asked. Where is the table for paupers?
(I have also used Latin to communicate with a priest with whom I didn't share any other language, although it was less surprising because it was at a spoken Latin event.)
Recently Liliana Segre, an Italian Auschwitz survivor and senator for life, was heavily criticized by (some) Italian politicians for proposing that the Parliament should set up a committee to investigate racism, anti-semitism and hate speech.
Since some critics were saying that she did not "love her country" (or something to that effect), she replied by recalling a brief conversation she had at Auschwitz with a prisoner from Eastern Europe. Both were teenagers and they were only able to communicate thanks to Latin. Patria mia pulchra est; Familia mea dulcis est; Cor meum et anima mea tristes sunt. (My motherland is beautiful; My family is sweet; My heart and soul are sad). She was still attached to the same country that sent her there.
His Russian colleague did not speak German, and he did not speak Russian. Latin was the only language in which they could communicate, and the first question by the Russian priest was:
re publica missus?
i.e., "[Were you] sent by the state?"