First evidence for settlement in the region of Zarnowiec came from 8 century BC. People living here were tied to Lausitian and East Pommeranian culture. In period of 7 to 10 century AD there was a settlement close to Zarnowieckie lake. The village called Sarnkow, Sarnowitz, Sarnowicz or Czarnowicz was first mentioned in sources in 13 century and was inhabited by Kashubes.
In the year 1215 Zarnowiec belonged to Cysters from Oliva Abbey, which founded here female monastery. That monastery received special economical and jurisdical (hm?) privileges from Mestwin II, duke of Pomorze (1279).
In 14th century Zarnowiec was with whole Gdansk Pommerania incorporated into Teuton Order state and belonged to comturia (?) from Danzig. In 1433 was raided by Hussites army. During 13th years war, in 1462 Polish army unedr commandment of Piotr Dunin defeat here Teuton army (see Battle of Zarnowiec, called also Battle of Swiecin). After the war Zarnowiec was part of King's Prussia (Prusy Krolewskie).
in 1590 it was taken by a female order of Benedictines from Chelmno. in 1617 they found an abbey here. In 1772 it was taken over by Prussia, after first partition of Poland. In 1834 abbey was liquidated. It was refounded in 1946 by a female order of Benedictines from Wilno (Vilnius).
TODO: Zarnowiec in Silesia, Zarnowieckie lake, nuclear plant,
This was translated from two different sources, it seems that quite similar, i don't know if they were in public domain, i guess so since i find very similar articles, sometimes even the smae sentences in few different places. I don't know also if citing facts from these articles is violation of their copyrighted work. Anyone eager to explain?