Other names, such as Óláfr hinn helgi, Olavus rex, and Olaf are used interchangeably (see the Heimskringla of Snorri Sturluson).

Åsta later married Sigurd Syr, with whom she had other children, including Harald Hardrada, who later reigned as king of Norway.

[12] Finally, many hagiographic sources describe St. Olaf, but these focus mostly on miracles attributed to him and cannot be used to accurately recreate his life.

The exact location of the battle is uncertain and the Finnish equivalent of Herdaler is unknown, but it has been suggested that it could be in Uusimaa, probably near present-day Ingå.

Skaldic poetry suggests he led a successful seaborne attack that took down London Bridge, though Anglo-Saxon sources do not confirm this.

Before leaving, Olaf was baptised in Rouen[8] in the pre-Romanesque Notre-Dame Cathedral by Richard's brother Robert the Dane, archbishop of Normandy.

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

In 1029, King Cnut's Norwegian regent, Jarl Håkon Eiriksson, was lost at sea and Olaf seized the opportunity to win back the kingdom.

But their regency was unpopular, and when Olaf's illegitimate son Magnus ('the Good') laid claim to the Norwegian throne, Svein and Ælfgifu were forced to flee.

[25] Modern historians generally agree[26] that Olaf was inclined to violence and brutality, and note that earlier scholars often neglected this side of his character.

[12][27] In his book The Conversion of Scandinavia, Anders Winroth argues that there was a "long process of assimilation, in which the Scandinavians adopted, one by one and over time, individual Christian practices.

Three factors are important: the later myth surrounding his role in the Christianisation of Norway, the various dynastic relationships among the ruling families, and the need for legitimisation in a later period.

What seems clear is that Olaf made efforts to establish a church organization on a broader scale than before, among other things by importing bishops from England, Normandy and Germany, and that he tried to enforce Christianity in the inland areas, which had the least communication with the rest of Europe, and which economically were more strongly based on agriculture, so that the inclination to hold on to the former fertility cult was stronger than in the more diversified and expansive western parts of Norway.

Numerous Danish churches were dedicated to Olaf during his reign, and the sagas give glimpses of the young king's efforts to promote the cult of his deceased father.

At this time, local bishops and their people recognised and proclaimed a person a saint, and a formal canonisation procedure through the papal curia was not customary; in Olaf's case, this did not happen until 1888.

But Olaf II died before the East-West Schism and a strict Roman Rite was not well-established in Scandinavia at the time.

[36] Another took place on the day of his death, when a blind man regained his sight after rubbing his eyes with hands stained with Olaf's blood.

The texts used for the liturgical celebration of St. Olaf during most of the Middle Ages were probably compiled or written by Eystein Erlendsson, the second Archbishop of Nidaros (1161–1189).

St Olave's Church, York, is referred to in the Anglo-Saxon Chronicle for 1055[39] as the place of burial of its founder, Earl Siward.

It also led to the naming of St Olave's Grammar School, which was established in 1571 and was in Tooley Street until 1968, when it moved to Orpington, Kent.

The village of St Olaves in Norfolk bears the name as it is the location of the remains of a 13th-century Augustinian priory dedicated to Olaf.

St. Olaf was also, together with the Mother of God, the patron saint of the chapel of the Varangians, the Scandinavian warriors who served as the bodyguard of the Byzantine emperor.

Its altarpiece contains a painting of the saint, shown as a martyr king defeating a dragon, representing victory over his pagan past.

It was originally a gift presented to Pope Leo XIII in 1893 for the golden jubilee of his ordination as a bishop by Norwegian nobleman and papal chamberlain Baron Wilhelm Wedel-Jarlsberg.

[45] Around the 12th century, folk traditions and iconography of Olaf absorbed elements of the gods Thor and Freyr from Norse mythology.

[46] Like Freyr, he became associated with fertility, which led to his adoption as a patron saint by farmers, fishermen, sailors and merchants of the Hanseatic League, who turned to him for good yield and protection.

[47] In Normandy, Saint Olaf represents an important figure and was chosen unofficially as the patron saint of the Normans, this term mainly designating the inhabitants of continental Normandy and of the Channel Islands, but also on a larger scale the inhabitants of the former Viking territories, namely the Scandinavian countries and, even more so, Norway.

There were also many kinships between the inhabitants of the brand new Norman state, as illustrated by the choice of Archbishop Robert II for the baptism of Olaf.

In some Norman parishes, Mass is celebrated on this day in honor of the saint and to mark the historical links that unite Normandy and Scandinavia.

[50] A statue of a young Olaf Haraldsson can be found erected in front of the Stave Church replica in the Norway Pavilion in Walt Disney World's Epcot.