The article by Euler titled "Solutio problematis ad geometriam situs pertinentis"(The Seven Bridges of Königsberg) is considered as the first work in both Topology and Graph Theory. However, in the original paper, I am not quite sure what language it was written in. I asked AI, and it told me it's in Latin. I'm a bit unsure because I'm writing a comprehensive article and need to ensure accuracy.
The language doesn't seem to be very common today, and I feel that English shares many similarities with it.