King Władysław Jagiełło – a historic person, king of Poland between 1381 and 1434 – was the first Polish king to recognize Sypniewski's Pomeranian nobility and to bestow them the Odrowąż coat of arms. It was very important event in Sypniewskis history and turning point in their genealogy, as from that moment on vast majority of Sypniewski's clan members were no longer identified as Pomeranian family, but chose to side with, and de facto became Poles. Sypniewski clan provided king Jagiełło (and later his son, king Casimir IV Jagiellon) with knights, arms, soldiers, supplies and money in their fight against Teutonic Order and they took active part in taking of Bydgoszcz, famous Battle of Grunwald, long Thirteen Years' War, and in every war fought by Poland since (i.e. Rotmistrz (Captain of Cavalry, equivalent of modern Colonel) Jan Stefan Sypniewski had briefly occupied Moscow in 1605 during Polish–Muscovite War)