Skwierczyński (different spellings: Skwirczyński, Śkwirczyński) of Ślepowron is the surname of a Polish szlachta (nobility) family from Podlaskie. The knight family came to the parish of Paprotnia in the area of Drohiczyn most likely from Masovia during the settlement led by Janusz I of Warsaw in the second half of the 14th century, or when PodlaskieUn transferred under the Lithuanian rule of Vytautas in 1405, who continued the settlement of Polish knights from areas of Masovia, as well as Łęczyca Voivodeship and Kuyavia in Podlaskie which had been deserted by the invasions of the Teutonic Knightss and Yotvingianss . The earliest documentation of the surname Skwierczyński is as old as the early 15th century. 15th century judal books make numerous mentions of the family. The oldest one relates to Jakusz of Skwierczyn (currently divided into Skwierczyn Ruski and Skwierczyn Lacki, and previously Skwierczyn Duży and Skwierczyn Mały) who donated part of Skwierczyn Mały to the church in Paprotnia in 1429 – brothers Stanisław and Szczepan of Skwierczyn witnessed the deed. Other representatives of the family from Skwierczyn appear in the land registry documents of Drohiczyn midway through 15th century – they are: Piotr (1452), Stanisław (1454), Wawrzyniec (1456), Mikołaj and Paweł (1458). In 1452, Piotr of Skwierczyn acted in the capacity of a witness to the heirs of Ugoszcz. Furthermore, an historian Władysław Semkowicz writes about Banach of Skwierczyn in 1453. Next, in 1465 Paweł Skwierczyński acted as a witness for Wojciech of Mogilnica and in 1469 a statement was taken from witnesses of Paweł Skwierczyński: Raczek Koza and Andrzej Nasiłowski, who won compensation in court for the death of his nephew. The latter also got in trouble with priest Wojciech, pastor of Wyrozęby, by supporting in 1476 the claims of priest Piotr, the vicar of Kożuchów. The misunderstandings arose most likely from the earlier accession of the village of Skwierczyn to the parish of Wyrozęby by way of decree granted by the bishop Marcin of Łuka. Later in 1481 Paweł Skwierczyński had a court case against Piotr, vicar of Wyrozęby. According to historian Tomasz Jaszczołt, in the years 1474–1484 mentions can be found of Jan Skwierczyński: Skwierczyński called Bujno, Jan, Wojciech and Paweł – brothers from Skwierczyn. We also know of Mikołaj Skwierczyński (1474). The judicial book of Drohiczyn for 1474–1484 mentions Mikołaj Skwierczyński as arbitrator for Błoński (1474), Paweł (1474) and Jan Skwierczyński, who had a court case