At the beginning of the 20th century, the Peregrine Falcon was a common species on the entire territory of Poland, although not abundant. It could be found most frequently in the area of Warmia and Mazury (North-eastern Poland). The literature about the Peregrine Falcon’s presence in pre-war Poland is scarce and so is the information about the species after World War II. At that time, Poland was in the middle of the region of the tree-nesting population, which extended from the North-eastern Germany to the lowlands of Belarus and Russia.