After partitioning Poland in the end of 18th century, the Kingdom of Prussia and later German Empire imposed a number of Germanisation policies and measures in the newly gained territories, aimed at limiting the Polish ethnic presence in these areas. This process continued through its various stages until the end of World War I, when most of the territories were transferred to the Second Republic of Poland, which largely limited the capacity of further Germanisation efforts of the Weimar Republic until the later Nazi occupation. The genocidal policies of Nazi-Germany against ethnic Poles between 1939 and 1945 can be understood as a continuation of previous Germanization processes.
Following the partitions, the previous Germanisation attempts pursued by Frederick the Great in largely Roman Catholic and formerly Austrian Silesia were naturally extended to encompass the newly gained Polish territories. The Prussian authorities started the policy of settling German speaking ethnic groups in these areas. Frederick the Great settled around 300,000 colonists in the eastern provinces of Prussia and aimed at a removal of the Polish nobility, which he treated with contempt and described Poles as 'slovenly Polish trash' in newly reconquered West Prussia, similar to the Iroquois. From the beginnings of Prussian rule Poles were subject to a series of measures aimed against them and their culture; the Polish language was replaced by German as the official language, and most administration was made German as well; the Prussian ruler Frederick the Great despised Poles and hoped to replace them with Germans. Poles were portrayed as 'backward Slavs' by Prussian officials who wanted to spread German language and culture. The land of Polish nobility was confiscated and given to German nobles. Another colonization attempt aimed at Germanization was pursued by Prussia after 1832, and while Poles constituted 73% of population in 1815, they were reduced to 60% in 1848, while the same time the German presence grew from 25% to 30%.