Wikipedia
Jankowski ( ; feminine: Jankowska, plural: Jankowscy) is the 13th most common surname in Poland (69,280 people in 2009). Many village estates were named Jankowa or Jankowice in 13th and 14th century Poland, producing at least twelve unrelated families with this surname. Over thirty place names with 'Jankow' (derived from Jan (John)) as a prefix remain in modern Poland. In most cases, the originator of the surname was a landowner of a reasonably sized estate (tens of hectares as a minimum but could be over one thousand hectares). Landowners often formed their surnames by adding the suffix '-ski', meaning 'of', to the estate name. They generally had considerable prestige and legal rights as the use of '-ski' indicated their adoption into the Polish nobility termed szlachta. To distinguish the different Jankowski szlachta families, they each used an additional identifier signifying their armorial crest or clan, termed 'herb' in Polish (see Boniecki, "Herbarsz Polski").