Frauenberg Cathedral with Vistula Lagoon in the background courtesy https://en.wikipedia.org/wiki/Frombork.
Frauenburg was founded as a stronghold on the Vistula Lagoon, off of the Baltic Sea. The area was conquered by the Teutonic Knights in 1224 and became known as East Prussia. Emperor Frederick the Second declared the stronghold subordinate to the Catholic Church and appointed Bishop William of Modena to oversee it. When the stronghold's lord died, his wife offered the town to the bishop, who named it Frauenburg in her honour (frau means lady in German).
In 1414 the town was plundered and burned in a war between Poland and the Teutonic Order. In 1454, during the Thirteen Years War its hill and cathedral were occupied by Jan Skalski. During the middle ages, most of Frauenburg's citizens were either merchants, farmers or fishermen. Its most famous resident was Nicolaus Copernicus. While he worked as a priest in the town for many years (1512-1516; 1522-1343) he was known for his work as an astronomer and mathematician. It was in the Baltic town that Copernicus wrote his famous De revolutionibus orbium coelestium.
The Red Army invades Frauenberg circa 1945 courtesy https://en.wikipedia.org/wiki/Heiligenbeil_Pocket.
In 1871, the region became part of the German Empire. In 1899, the railway came to town connecting Elbing and Braunsberg through Frauenburg. In 1945, war came to Frauenberg. Many German residents fled the city via the frozen Vistula Lagoon, some drowning en route (see "Death on the Baltic" at http://alinefromlinda.blogspot.ca/2013/11/death-on-baltic.html). A vicious battle ensued between the Red Army and the Wehrmacht and 70% of the city was destroyed. After the Second World War came to a close, most Germans were expelled from the area as part of the Potsdam Agreement. Frauenberg, now renamed Frombork, became part of Poland; it was resettled by Poles, many of whom were expelled from other parts of Poland by the Soviets (http://alinefromlinda.blogspot.ca/2016/03/orderly-and-humane-expulsion-of-germans.html).
Frauenberg was not unlike many German cities which were reduced to rubble by the Allied bombings during World War II. However, whereas cities like Berlin, Cologne and Dresden were rebuilt by the rubble women (see "Trummerfrauen" http://alinefromlinda.blogspot.ca/2011/10/trummerfrauen.html) Frauenberg was rebuilt by Polish Boy Scouts. The project, which lasted seven years, was named Operation 1001. The impetus was the 500th birthday of Copernicus in 1973 (see newspaper article about the occasion at https://news.google.com/newspapers?nid=2512&dat=19730221&id=6OVcAAAAIBAJ&sjid=slkNAAAAIBAJ&pg=4784,2704730&hl=en).
Frombork monument to Nicolaus Copernicus, whose revolutionary thinking at the time led to his discovery that the earth orbits around the sun (not the reverse as was previously thought) courtesy https://en.wikipedia.org/wiki/Nicolaus_Copernicus_Monument,_Toru%C5%84.