Jomsborg

Jomsborg or Jómsborg () was a semi-legendary Viking stronghold at the southern coast of the Baltic Sea (medieval Wendland, modern Pomerania), that existed between the 960s and 1043. Its inhabitants were known as Jomsvikings. Jomsborg's exact location, or its existence, has not yet been established, though it is often maintained that Jomsborg was somewhere on the islands of the Oder estuary. Historian Lauritz Weibull dismissed Jomsborg as a legend.
The only medieval source that mentions a precise location of Jomsborg is "Gesta Wulinensis ecclesiae pontificum" that was discovered in the autumn of 2019.
Location.
Jomsborg is often thought to be identical with the present-day town of Wolin (also Wollin) on the southeastern tip of the isle of Wolin in northwestern Poland, probably located at Srebrna Góra hill north of the town. In the Early Middle Ages, modern Wolin was the site of a multi-ethnic emporium (then known as "Jumne" or "Julin"). The Nordic sagas use "Jómsborg" exclusively, while medieval German histories use "Jumne" or "Julin", with the alternate names, some of which may be spelling variants, "vimne", "uimne", "Jumneta", "Juminem", "Julinum", "uineta", "Vineta" and "Vinneta".
In 1931/32, Pomeranian historian Adolf Hofmeister (1883-1956) suggested, through comparison of the events reported by the different chronicles, that all these terms describe the same place, which is at or near the modern town of Wolin. However, this is by no means universally accepted; Professor and historian Steven Fanning writes: "The Trelleborg-type fortresses of Denmark have been taken to be actual examples of Jómsborg-style camps of such warriors and Wolin in Poland was believed to be the actual Jómsborg. However, all such attempts to locate Jómsborg or encampments of the Jómvikings have failed, leading many to doubt that Jómvikings ever existed outside of literature." According to Władysław Filipowiak there are several dated sources which attest to the presence of a company of armed Vikings at the end of the 10th century in Wolin, who may have been installed there as mercenaries by the Polish king Bolesław the Brave.
Other theories see Jomsborg in the northwest of nearby Usedom island, on lands now submerged. The small islands in this area are remnants of a long stretch of land between Usedom and Rügen, which fell victim to storm floods in the early 14th century. Suspected locations in this area are the Veritas grounds between the petty islands of Ruden and Greifswalder Oie, and the Peenemünde shoals. While Viking Age jewelry has been found at the site, archaeological evaluation of these theories has not yet been possible.
Fortress.
According to the "Knytlingasaga" and "Fagrskinna", Jomsborg was built by the Danish king Harold Bluetooth (910-985/86) in the 960s. The Jomsvikinga Saga mentions Danish Viking Palnatoki as its founder.
In medieval records, Jomsborg is described as a fortress with a harbour. The harbour was overseen by a stone tower mounted with catapults, built on an arch spanning over the harbour entrance which could be closed by an iron gate. According to the oldest records, the harbour had space for three ships, later records give a capacity of up to 360 ships.
According to the "Heimskringla", Jomsborg was destroyed in 1043 by Dano-Norwegian king Magnus the Good. The fortress was burned down, and many of the inhabitants were killed.
Jomsvikings.
The Jomsborg Vikings (Jomsvikings) were composed of selected warriors, adhered to a special codex, and were loyal only to their leader. Most records list as jarl of Jomsborg, Sigvald(i), son of petty king Strut-Harald of then Danish Scania. Sigvald died some time before 1010.
Curmsun Disc.
A golden disc bearing the name of Harald Bluetooth and Jomsborg appeared in Sweden in autumn 2014. The disc, also called the Curmsun Disc, is made of high gold content and has a weight of 25,23 gram. On the obverse there is a Latin inscription and on the reverse there is a Latin cross with four dots surrounded by an octagonal ridge. The inscription reads: "+ARALD CVRMSVN+REX AD TANER+SCON+JVMN+CIV ALDIN+" and translates as "Harald Gormsson king of Danes, Scania, Jomsborg, diocese of Aldinburg".
It is assumed that the disc was a part of a Viking hoard found in 1841 in the Polish village Wiejkowo near the town of Wolin by Heinrich Boldt, the maternal great-great-grandfather of Hollywood actors and producers Ben Affleck and Casey Affleck.
Gesta Wulinensis ecclesiae pontificum.
The location of Jomsborg has been a topic of debate for centuries. In the autumn of 2019 a new historical chronicle was found called , and this chronicle, apart from giving various information on the Jomsvikings and Jomsborg, also tells about the location for where Jomsborg once was to be found. The existence of the chronicle had been known since 2014 by a number of references that the rector from the parish of Groß Weckow (now Wiejkowo) made in the 1840s and 1850s in his notebooks, but the chronicle itself was unknown until a translation of the complete chronicle was found in 2019. The Swedish archaeologist Sven Rosborn has visited the location and confirms, that it both matches the descriptions of Jomsborg from the various sagas and chronicles and that various things that could be found on the surface of the location seem to match the period of time in which Jomsborg existed. The relevant parts of "Gesta Wulinensis ecclesiae pontificum" will be made available in a new book, that could be published in 2021 or perhaps later.