Conversation so far:
Can you tell me about Vlachs in the 13th century?
In 1213 an army of Romans (Vlachs), Transylvanian Saxons, and Pechenegs, led by Ioachim of Sibiu, attacked the Bulgars and Cumans from Vidin.
Can you tell me what led to this?
At the end of the 13th century, during the reign of Ladislaus the Cuman, Simon de Keza wrote about the Blacki people and placed them in Pannonia with the Huns.
Was there anything else interesting about that?
Catholic German-speaking settlers from Rhineland and Mosel Valley (known as Transylvanian Saxons) began to settle in the Orthodox region.

Question: What happened after they began to settle in the Orthodox region?
Self-contained rewrite: What happened after Catholic German-speaking settlers from Rhineland and Mosel Valley began to settle in the Orthodox region?