The first German colonists arrived in the late 12th century, and large-scale German settlement started in the early 13th century during the reign of Henry I[14] (Duke of Silesia from 1201 to 1238 and of all-Poland from 1232 to 1238). After the era of German colonisation, the Polish language still predominated in Upper Silesia and in parts of Lower and Middle Silesia north of the Odra river. Here the Germans who arrived during the Middle Ages became mostly Polonized; Germans dominated in large cities and Poles mostly in rural areas.