At first, the Olenders were settlers who came from the Netherlands and Friesland to Poland and settled in Royal Prussia in the 16th century. They were highly skilled in land drainage and represented a high agricultural culture. In return for efficient farming, they were granted personal freedom. Over time, the term adhered to all settlers, including Poles, who enjoyed the privileges of Frisian colonists and other amenities under the Olender settlement law.

The Olender colonisation developed in Poland from the 16th century until the middle of the 19th century. They established about 1700 settlements, of which only 300 were built by ethnic Dutch. The Olenders appeared in Mazovia only in the 18th century, choosing its northern and central areas, in the valley of the middle Vistula, from the mouth of the Skra to the mouth of the Bug-Narwia. Their task was to develop the marshy wastelands in the Vistula valley through land drainage. This colonisation also developed up the Vistula to the vicinity of Dęblin. According to Zdzisław Skrok, the only evidence of their presence in the Mazovia region are the names of the villages Holendry and Holendry Piotrkowskie, on the left and right bank of the Vistula respectively.

Evidence of their life can also be found in the area of Warsaw, in the municipality of Wilanów, in its formerly part – village Kępa Zawadowska. It was founded at the beginning of the 19th century by the Potocki family, the owners of Wilanów, who wanted to develop the wasteland on the Vistula. Thanks to them, the Olenders soon appeared in the village, starting to build their characteristic houses, erected on terps, i.e. artificially raised hills.

Their buildings looked like sailing ships set with their heads to the wind. They always faced the Vistula and had double, reinforced doors to prevent water from entering through them. Another type of protection against flooding was the laying of dykes.

As Jan Kazimierczyk has proved, most of the Olenders of Kępa Zawadowska were of German origin and German religion. Their relations with the surrounding Polish peasants were good. This is evidenced by an incident during World War I, when the Olenders were deported by the Russians deep into the Empire. At that time the local people took over their fields on lease but returned them on their comeback.

Relations broke down in the 1930s when Nazi ideology reached the Vistula.