So basically Philippe Mousket mentions an interesting thing in his "Rhymed Chronicle." He mentions that in 1242 a "king from the land of Vlachs" defeated the Mongols, much to the resounding joy of all who heard the news. This would technically be the only European victory against the Mongols. Here are my sources:
Mousket specifically writes: "Que li rois de la tiere as Blas" (the king from the land of Vlachs). He mentions that the Mongol army was defeated "at the passes" which I assume are the passes of the Carpathian mountains. Now, what is interesting is that French chronicles also wrote of the 2nd Bulgarian Empire as the Empire of Vlachs and Cumans, and Philippe Mousket personally wrote of Joannitsa/Kaloyan as "Et la seconde ot Jehanins Sires des Blas et des Comins" (John the IInd Sire of the Vlachs and Cumans). The complete phrase about the "King from the Land of Vlachs" is (in Romanian) "a venit veste despre tatari, cu mare bucurie in lumea toata, cum ca regele din tara vlahilor i-a invins la trecatori" ("news arrived of the tatars, with great joy of the whole world, about how the king from the land of vlachs defeated them at the passes.") [original French: des Tartares revint noviele / Ki partot le monde fu biele / Que li rois de la tiere as Blas / les ot descomfis a un pas]
So who was this guy? Was he:
a) The 2nd Bulgarian Emperor (who also ruled over a large number of Vlachs)
b) A Romanian/Vlach voievode from South of the Carpathians in modern Wallachia.
c) A Romanian/Vlach cneaz from the Terra Blachorum ("land of Vlachs", Southern Transylvania)
d) Complete made-up BS. Mousket was pissed that Europe got its ass kicked by the Mongols and he needed a hero.