At the end of the 13th century all regions in Silesia except for some small outer zones in the east were affected by colonization. Because of migration Silesia's population density, the forms of settlement and the population changed dramatically. Large, well-planned villages became the norm. A network of almost 130 towns covered the country almost evenly, with a distance from town to town of approximately . The "Weichbild" constitution replaced the old Slavic castellany constitution. Every village built its own church (at the end of the 13th century numbering 1,200) the network of parishes also became much more dense, and the diocese was split into the archdeaconries of Breslau, Glogau, Opole and Liegnitz. There are different estimates of the population of Silesia in the 14th century. They vary from approximately 500,000 people, to over 1,000,000 in 1400 and 1,200,000 in 1500. It is estimated that in the year 1400 some 30,000 Czechs and 30,000 Germans inhabited Upper Silesia along with a Polish population of 240,000 (80%). In Lower Silesia the number of Poles and Germans has been estimated as around 375,000 for each language group. After the era of German colonization, the Polish language was still predominant in Upper Silesia and parts of Lower and Middle Silesia north of the Oder river. Here, the Germans who arrived during the Middle Ages were mostly Polonized; the Germans dominated large cities and Poles lived mostly in rural areas. The Polish speaking territories of Lower and Middle Silesia, commonly described until the end of the 19th century as the "Polish side" were mostly Germanized in the 18th and 19th centuries, except for some areas along the northeastern frontier.