Adam of Bremen in the context of "Etymology of Denmark"

The term Norwegian Realm (Old Norse: *Noregsveldi, Bokmål: Norgesveldet, Nynorsk: Noregsveldet) and Old Kingdom of Norway refer to the Kingdom of Norway's peak of power in the 13th century after a long period of civil war before 1240. The kingdom was a loosely unified nation including the territory of modern-day Norway, modern-day Swedish territory of Jämtland, Herjedalen, Ranrike (Bohuslän) and Idre and Särna, as well as Norway's overseas possessions which had been settled by Norwegian seafarers for centuries before being annexed or incorporated into the kingdom as 'tax territories'. To the North, Norway also bordered extensive tax territories on the mainland. Norway, whose expansionism starts from the very foundation of the Kingdom in 872, reached the peak of its power in the years between 1240 and 1319.

At the peak of Norwegian expansion before the civil war (1130–1240), Sigurd I led the Norwegian Crusade (1107–1110). The crusaders won battles in Lisbon and the Balearic Islands. In the Siege of Sidon they fought alongside Baldwin I and Ordelafo Faliero, and the siege resulted in an expansion of the Kingdom of Jerusalem. Leif Erikson, an Icelander of Norwegian origin and official hirdman of King Olaf I of Norway, explored America 500 years before Columbus. Adam of Bremen wrote about the new lands in Gesta Hammaburgensis ecclesiae pontificum (1076) when meeting Sweyn I of Denmark, but no other sources indicate that this knowledge went farther into Europe than Bremen, Germany. The Kingdom of Norway was the second European country after England to enforce a unified code of law to be applied for the whole country, called Magnus Lagabøtes landslov (1274).

Harald Sigurdsson (Old Norse: Haraldr Sigurðarson; c. 1015 – 25 September 1066), also known as Harald III of Norway and given the epithet Hardrada in the sagas, was King of Norway from 1046 to 1066. He unsuccessfully claimed the Danish throne until 1064 and the English throne in 1066. Before becoming king, Harald spent 15 years in exile as a mercenary and military commander in Kievan Rus' and chief of the Varangian Guard in the Byzantine Empire. In his chronicle, Adam of Bremen called him the "Thunderbolt of the North".

In 1030, the fifteen-year-old Harald fought in the Battle of Stiklestad alongside his half-brother Olaf Haraldsson. Olaf sought to reclaim the Norwegian throne, which he had lost to Danish king Cnut two years previously. Olaf and Harald were defeated by forces loyal to Cnut, and Harald was forced into exile to Kievan Rus'. Thereafter, he was in the army of Grand Prince Yaroslav the Wise, becoming captain, until he moved on to Constantinople with his companions around 1034. In Constantinople, he rose quickly to become the commander of the Byzantine Varangian Guard, seeing action on the Mediterranean Sea, in Asia Minor, Sicily, possibly in the Holy Land, Bulgaria and in Constantinople itself, where he became involved in the imperial dynastic disputes. Harald amassed wealth whilst in the Byzantine Empire, which he shipped to Yaroslav in Kievan Rus' for safekeeping. In 1042, he left the Byzantine Empire, returning to Kievan Rus' to prepare to reclaim the Norwegian throne. In his absence the Norwegian throne had been restored from the Danes to Olaf's illegitimate son Magnus the Good.

The Polans (Polish: Polanie; Latin: Polani, Polanos), also known as Polanians or Western Polans (Polish: Polanie Zachodni; Latin: Polani Occidentis), were a West Slavic and Lechitic tribe who inhabited the Warta River basin of the contemporary Greater Poland region starting in the 6th century.

They were one of Central Europe's main tribes and closely related to the Vistulans, Masovians, Czechs and Slovaks. According to Zygmunt Gloger, their name was derived from the word "pole", meaning "field", thus denoting them as "men of the fields".

The ethnonyms for the Poles (people) and Poland (their country) include endonyms (the way Polish people refer to themselves and their country) and exonyms (the way other peoples refer to the Poles and their country). Endonyms and most exonyms for Poles and Poland derive from the name of the West Slavic tribe of Polans (Polanie), while in some languages the exonyms for Poland to derive from the name of another tribe – the Lendians (Lędzianie).

The Eider (German: Eider [ˈaɪdɐ] ; Danish: Ejderen; Latin: Egdor or Eidora) is the longest river in the German state of Schleswig-Holstein. The river starts near Bordesholm and reaches the southwestern outskirts of Kiel on the shores of the Baltic Sea, but flows to the west, ending in the North Sea. The lower part of the Eider was used as part of the Eider Canal until that canal was replaced by the modern Kiel Canal.

In the Early Middle Ages the river is believed to have been the border between the related Germanic tribes, the Jutes and the Angles, who along with the neighboring Saxons crossed the North Sea from this region during this period and settled in England. During the High Middle Ages the Eider was the border between the Saxons and the Danes, as reported by Adam of Bremen in 1076. For centuries it divided Denmark and the Holy Roman Empire. Today it is the border between Schleswig, Holstein and Eiderland, the northern and southern parts, respectively, of the modern German state of Schleswig-Holstein.

Estrid Svendsdatter of Denmark (also known as Estrith or Astrith; sometimes called Margaret; fl. 1017–1032; c. 990s – after 1057 and before 1073) was a prominent Danish princess and titular queen of the Jelling dynasty, half-sister of Cnut the Great and wife of the magnate Ulf Jarl. She was the mother of Sweyn II Estridsen, during whose reign she was commonly styled dronning (“queen”) in Denmark, though she was never queen regnant nor a king's consort. Through Estrid, Sweyn traced his claim to the Danish throne and founded the matronymic House of Estridsen, which ruled from 1047 to 1412.

Medieval sources diverge on several points of her life. She was a daughter of Sweyn Forkbeard, but her mother is variously identified in sources as Sigrid the Haughty or, in earlier scholarship, as the Slavic princess sometimes called Gunhild of Wenden, a view now generally rejected. After Sweyn's death in 1014, Estrid came under Cnut's guardianship. He married her to a son of Grand Prince Vladimir the Great or Yaroslav the Wise, but the prince died shortly afterwards. Several western chroniclers, including Rodulfus Glaber and Adam of Bremen, record a proposed or short-lived marriage with the duke of Normandy (probably Robert I, Duke of Normandy), though the precise details remain uncertain. By the early 1020s, she was married to the English magnate Ulf Thorgilsson, who later served as regent in Denmark. By marriage she was thus, successively, a Russian princess, duchess of Normandy and a Danish noblewoman.

The Helsingør–Helsingborg ferry route ("HH route") is a shipping route connecting Helsingør (Elsinore), Denmark and Helsingborg, Sweden across the northern, and narrowest part of the Øresund. Due to the short distance, which is less than 3 nautical miles, it is one of the world's busiest international car ferry routes, with around 70 daily departures from each harbour. The oldest-known written mention of the route dates to the German traveller Adam of Bremen in the 11th century, but it has likely been in use much longer. Before 1658, the route was a domestic Danish route. For several centuries, the route has been run regularly by various Danish shipping lines. Its significance grew during the 1950s, but since the inauguration of the Øresund Bridge in 2000, at the southern end of the Øresund, it has lost some significance but remains as one of the world's most important ferry routes, particularly as a cheaper alternative to the bridge tolls. Since 1952, passports have not been required for citizens of the Nordic Passport Union countries. Since 2001, when both countries became members of the Schengen Area, passports are not needed for anyone.

Gesta Hammaburgensis ecclesiae pontificum (Medieval Latin for "Deeds of the Bishops of Hamburg") is a historical treatise written between 1073 and 1076 by Adam of Bremen, who made additions (scholia) to the text until his death (possibly 1081; before 1085).It is one of the most important sources of the medieval history of Northern Europe, and the oldest textual source reporting the discovery of coastal North America.

It covers the entire period known as the Viking Age, from the foundation of the bishopric under Willehad in 788 until the rule of prince-bishop Adalbert in Adam's own time (1043–1072).The text focuses on the history of the Hamburg-Bremen diocese and its bishops. As the bishops had jurisdiction over the missions to Scandinavia, it also gives a report of the Norse paganism of the period.