The region of Kiev will dominate the state of Kievan Rus' for the next two centuries.

The grand prince of Kiev controls the lands around the city, and his theoretically subordinate relatives ruled in other cities and pay him tribute.

The zenith of the state's power comes during the reigns of Prince Vladimir (r. 978-1015) and Prince Yaroslav (the Wise; r. 1019-54).

Both rulers continue the steady expansion of Kievan Rus' that had begun under Oleg.

To enhance their power, Vladimir marries the sister of the East Roman emperor, and Yaroslav arranges marriages for his sister and three daughters to the kings of Poland, France, Hungary, and Norway.

Vladimir's greatest achievement is the Christianization of Kievan Rus', a process that begins in 988.

He builds the first great edifice of Kievan Rus', the Desyatinnaya Church in Kiev.

Yaroslav promulgates the first East Slavic law code, Rus'ka pravda (Justice of Rus'); builds cathedrals named for St. Sophia in Kiev and Novgorod; patronized local clergy and monasticism; and is said to have founded a school system.

Yaroslav's sons develop Kiev's great Peshcherskiy monastyr' (Monastery of the Caves), which functions in Kievan Rus' as an ecclesiastical academy.

Vladimir's choice of Eastern Orthodoxy reflects his close personal ties with Constantinople, which dominate the Black Sea and hence trade on Kiev's most vital commercial route, the Dnepr River.

Adherence to the Eastern Orthodox Church has long-range political, cultural, and religious consequences.

The church has a liturgy written in Cyrillic and a corpus of translations from the Greek that had been produced for the South Slavs.

The existence of this literature facilitates the East Slavs' conversion to Christianity and introduces them to rudimentary Greek philosophy, science, and historiography without the necessity of learning Greek.

In contrast, educated people in medieval Western and Central Europe learn Latin.

Because the East Slavs learn neither Greek nor Latin, they are isolated from Byzantine culture as well as from the European cultures of their neighbors to the west.

England breaks away from Danish control in 1035 and Denmark falls into disarray for some time.

Sweyn Estridsen's son, Canute IV, raids England for the last time in 1085.

He plans another invasion to take the throne of England from an aging William I.

He calls up a fleet of one thousand Danish ships, sixty Norwegian long boats, with plans to meet with another six hundred ships under Count Robert of Flanders in the summer of 1086.

Canute, however, is beginning to realize that the imposition of the tithe on Danish peasants and nobles to fund the expansion of monasteries and churches and a new head tax (Danish: nefgjald) has brought his people to the verge of rebellion.

Canute takes weeks to arrive at Struer where the fleet has assembled, but he finds only the Norwegians still there.

Canute's nephew Sweyn Estridson (1020–74) re-establishes strong royal Danish authority and builds a good relationship with Archbishop Adalbert of Hamburg-Bremen—at this time the Archbishop of all of Scandinavia.

Sweyn Forkbeard, the son of Harald, mounts a series of wars of conquest against England in retaliation for the St. Brice's Day massacre of Danes in England.

By 1014, England has completely submitted to the Danes.

However, distance and a lack of common interests prevents a lasting union, and Harald's son Cnut the Great barely maintains the link between the two countries, which completely break up during the reign of his son Hardecanute.

A final attempt by the Norwegians under Harald Hardrada to reconquer England fails, but does pave the way for William the Conqueror's takeover in 1066.

Following the death of Canute the Great, Denmark and England are left divided and despite some attempts are never reunited.

Northwest Europe (964 – 1107 CE): Norman Conquest, Insular Kingdoms, and North Sea Networks

Geographic and Environmental Context

Northwest Europe includes Iceland, Ireland, the United Kingdom, the Faroe, Shetland, and Orkney Islands, the Channel Islands, and the western coastal zones of Norway and Denmark (west of 10°E).

• Anchors: London–York–Winchester, Dublin–Waterford–Cork, Bergen–Trondheim, Orkney–Shetland–Faroe–Iceland, Channel ports (Southampton, Dover).

Climate and Environmental Shifts

• Warm conditions supported population growth; herring shoals and cod grounds underpinned fisheries from North Sea to Iceland.

Societies and Political Developments

• England: consolidation under Anglo-Saxon kings (Æthelred II, Cnut the Great, 1016–1035, Edward the Confessor).

• Norman Conquest (1066): William seized England; castles, feudal estates, Domesday Book (1086).

• Ireland: Norse towns remained semi-autonomous; Irish high-kings (Brian Boru, d. 1014 at Clontarf).

• Scotland: Kings Malcolm II–III consolidated Lowlands; Norse jarls remained strong in Orkney/Hebrides.

• Norway/Denmark: Cnut’s North Sea Empire (England–Denmark–Norway); later Norway consolidated under Olaf Haraldsson (St. Olaf, d. 1030).

• Iceland: Christianization (c. 1000), Althing maintained self-rule under Norwegian overlordship by late 11th c.

Economy and Trade

• London grew as a major European port.

• Dublin, York thrived on slave trade, silver, and hides.

• North Sea commerce: wool, cloth, salt, fish; Norwegian timber and iron traded south.

• Flemish cloth towns (Ghent, Bruges, just across boundary in Atlantic West Europe) were key markets for English wool.

Belief and Symbolism

• Christianization of Scandinavia; churches founded across Norway, Denmark, and Iceland.

• Monastic expansion in England, Ireland, Scotland; Norman Romanesque architecture flourished.

Long-Term Significance

By 1107, the Norman monarchy dominated England; Scandinavia and Iceland were Christianized; the North Sea was a connected political and economic system.

Norse traditions are slowly replaced by Christian ones in the late tenth and early eleventh centuries.

One of the most important sources for the history of the eleventh century-Vikings is the treaty between the Icelanders and Olaf Haraldsson, king of Norway circa 1015 to 1028, later known as Saint Olaf.

This is largely attributed to the missionary kings Olaf Tryggvasson and St. Olaf.

Haakon the Good had been Norway's first Christian king, in the mid-tenth century, though his attempt to introduce the religion had been rejected.

Olaf Tryggvasson, born sometime in between 963–969, sets off raiding in England with three hundred and ninety ships.

He attacks London during this raiding.

Arriving back in Norway in 995, Olav lands in Moster, where he builds the first Christian church in Norway.

From Moster, Olav sails north to Trondheim where he is proclaimed King of Norway by the Eyrathing in 995.

Harald III of Norway lands in Northern England in September 1066 with a force of around fifteen thousand men and three hundred longships (fifty men in each boat).

With him is Earl Tostig, who has promised him support.

Harold Godwinson defeats and kills Harald III of Norway and Tostig and the Norwegian force at the Battle of Stamford Bridge.

William of Normandy invades England with a force of Normans on September 28, 1066, in a campaign known as the Norman Conquest.

On October 14, after having marched his exhausted army all the way from Yorkshire, Harold fights the Normans at the Battle of Hastings, where England's army is defeated and Harold is killed.

Further opposition to William in support of Edgar the Ætheling soon collapses, and William is crowned king on Christmas Day 1066.

He immediately revolts on all sides and a half-hearted Danish invasion, but after four years he is able to subdue all resistance and establish an enduring regime.

He now goes about imposing his superiority over Scotland and Wales, forcing each to recognize him as overlord.

Ireland’s High King Brian Boru divorces Queen Gormflaith some time during the 1010s, and she begins to engineer opposition to the High King.

Relations between Brian and Leinster have become so strained that revolt breaks out among the Leinstermen around 1012.

Eric Haakonsson leaves Norway in 1014 or 1015 and joins Cnut, later known as Canute the Great, for his campaign in England.

The Scandinavian invasion fleet lands at Sandwich in midsummer 1015 where it meets little resistance.

Cnut's forces move into Wessex and plunder in Dorset, Wiltshire and Somerset.

Alderman Eadric Streona assembles an English force of forty ships and submits to Cnut.

The Scandinavian army moves over the Thames in early 1016 into Mercia, plundering as it goes.

Prince Edmund attempts to muster an army to resist the invasion but his efforts are not successful.

Cnut's forces continue unhindered into Northumbria where Uhtred the Bold, earl of Northumbria, is murdered.

The great north English earldom is given by Cnut to Eric after he wins control of the North.

The invading army turns south again towards London.

King Æthelred the Unready dies before they arrive, and Prince Edmund is chosen king.

The Scandinavian forces besiege London.

After several battles, Cnut and Edmund reach an agreement to divide the kingdom, but Edmund dies a few months later.

Cnut, as the undisputed king of all England in 1017, divides the kingdom into four parts.

Wessex he keeps for himself, East Anglia he gives to Thorkell, Northumbria to Eric and Mercia to Eadric.

Cnut has Eadric executed as a traitor later in the same year.

The narrative in Snorri Sturluson's Heimskringla, from about 1225, is a widely used description of the life of Olaf Haraldsson, a future king of Norway.

Born in Ringerike, his mother was Åsta Gudbrandsdatter, and his father was Harald Grenske, great-great-grandson of Harald Fairhair, the first king of Norway.

Harald Grenske died when Åsta Gudbrandsdatter was pregnant with Olaf.

She later married Sigurd Syr, with whom she has had other children, including Harald Hardrada, who will reign as a future king of Norway.

According to the sagas, Olaf had landed in 1008 on the Estonian island of Saaremaa (Osilia), home of the Estonian pirates also known as the Eastern Vikings.

The Osilians, taken by surprise, had at first agreed to pay the demands made by Olaf, but then gathered an army during the negotiations and attacked the Norwegians.

Olaf, who would have been thirteen years old at the time, nevertheless won the battle.

Scholars have questioned many of his exploits extolled in the sagas.

As a teenager, he had gone to the Baltic, then to Denmark and later to England.

Skaldic poetry suggests he led a successful sea-borne attack which pulled down London Bridge, though this is not confirmed by Anglo-Saxon sources.

This may have been in 1014, during the restoration of London and the English throne to Æthelred the Unready and removal of Cnut.

Olaf sees it as his call to unite Norway into one kingdom, a task in which his ancestor Harald I of Norway had largely succeeded.

On the way home, he had wintered with Duke Richard II of Normandy, a region that had been conquered by the Norseman in the year 881.

Duke Richard is himself an ardent Christian, and the Normans had also previously converted to Christianity.

Before departing, Olaf had been baptized in Rouen.

Taking advantage of the absence, in England, of Erik, earl of Hladir, the pro-Danish ruler of the Trondelag, he sails back to Norway with an army in 1015 and declares himself king, obtaining the support of the five petty kings of the Uplands.

He had defeated Earl Sweyn, hitherto the virtual ruler of Norway, in 1016 at the Battle of Nesjar.

He founded the town Borg by the waterfall Sarpsfossen, later to be known as Sarpsborg in Østfold county, Norway.

Within a few years he has won more power than had been enjoyed by any of his predecessors on the throne.

He has annihilated the petty kings of the South, subdued the aristocracy, asserted his suzerainty in the Orkney Islands, and conducted a successful raid on Denmark.

He makes peace with King Olof Skötkonung of Sweden and is for some time engaged to his daughter, Princess Ingegerd Olofsdotter, though without Olof's approval.

Olaf in 1019 marries Astrid Olofsdotter, Olof's illegitimate daughter and half-sister of his former fiancée.

Their daughter Wulfhild in 1042 will marry Ordulf, Duke of Saxony.

Numerous royal, grand ducal and ducal lines are descended from Ordulf and Wulfrid, including the House of Saxe-Coburg and Gotha.

Maud of Wales, daughter of King Edward VII of the United Kingdom, was the mother of King Olav V of Norway, so Olav and his son Harald V, king of Norway from January 1991, are thus descended from Olaf.