 From 1138, Mazovia was governed by a separate branch of the Piast dynasty and when the last ruler of the independent Duchy of Mazovia died, it was fully incorporated to the Polish Crown in 1526.During the Polish–Lithuanian Commonwealth over 20% of Mazovian population was categorized as petty nobility.Between 1816 and 1844, the Mazovian Governorate was established, which encompassed the south of the region along with Łęczyca Land and south-eastern Kuyavia.