According to written sources, when moving to Roskilde, Bluetooth built a royal farm and next to it, a small stave church, dedicated to the Holy Trinity.

In Adam of Bremen's Gesta Hammaburgensis ecclesiae pontificum, there is an account of how the king's son, Sweyn Forkbeard, raised a rebellion against him, forcing him to flee to Jomsborg.

Though the sources differ, this happened either inside the church (Chronicon Roskildense) or at the royal farm (Saxo Grammaticus's Gesta Danorum).

When Sweyn Forkbeard conquered England in 1013, he began sending English bishops to Denmark, a process which was continued by his successor Cnut the Great.

The earliest known bishop of Roskilde was Gerbrand, who had been a cleric with Cnut the Great, and who was intercepted by the Archbishop of Hamburg-Bremen's men when he sailed to Denmark in 1022.

Legend holds that while they were resting after their arrival, St Lucius, who had been pope from 253 to 255, appeared before them and told them that he had been chosen to be the patron saint of Roskilde until the end of time.

On their return, while the canons were sailing through the Great Belt, their ship came under attack by a powerful demon that had long lurked in Danish waters.

Another item of the period, a seal carved from a walrus tusk, depicting St Lucius between the twin towers of the cathedral, has been dated to the early 12th century.

[10] Absalon's successor, Peder Sunesen, embracing the new French Gothic style, later made significant changes to the plans, tearing down the choir towers and reducing the width of the transept.

[11] But new research points to Peder Sunesen as the main initiator and hence instead of rebuilding it, it was constructed in the transition period between Romanesque and Gothic show elements from both styles in the cathedral.

[12] With the exception of the two towers on the west facade, the cathedral was completed by 1280, and work on the interior proceeded, slowed by a fire in 1282 which also destroyed several of the canons' houses in the area.

But the following year bishop Peder Jensen Lodehat, who had been the queen's chancellor and religious advisor, brought her body to Roskilde Cathedral.

In his "Chronica novella", German chronicler de:Hermann Korner describes the vast, three-day-long burial ceremony involving King Eric VII, several noblemen, the Archbishop of Lund, and all of the Danish bishops.

While the cathedral suffered financial hardship, having been forced to give away all its property (which at the time included one in every four farms on Zealand and 30 large estates), it was endowed with a variety of gifts from Christian IV: The altarpiece (between 1555 and 1623), a royal box ca 1600, the pulpit in 1610, his own burial chapel in 1614, the construction of the iconic twin spires in 1633 and finally a grand Renaissance sandstone entrance portal in 1635.

During firefighting operations, members of the civil defense and church staff covered the canons' chairs, the altar, and the sarcophagi in the retrochoir with damp fire blankets, hoping to prevent damage to the invaluable items.

The Defence Minister of Denmark ordered a complete ban on jet operations in the area, pending investigations into whether the vaults were in danger of collapsing.

In fact, they were never added, and when the Spanish sacked Antwerp in November 1576, the monument was held until the widow of Cornelis Floris paid a ransom.

[26] Frederick II's monument, crafted from the same materials, was built 1594–1598 by the Flemish sculptor Gert van Egen, who was a pupil of Cornelis Floris and was a resident of Elsinore.

[29] The upper floor is currently used as a museum, displaying various artifacts such as old coloured stained glass windows and giving a thorough walkthrough of the history of the cathedral.

Construction of the chapel was ordered by Christian IV himself in 1613, after the death of his Queen Anne Cathrine the year before, and upon realising that space inside the cathedral was running out.

Construction of the chapel was started by C. F. Harsdorff in 1774, possibly using early sketches made during his travels to Rome 1762–1764, but due to a lack of funding the work was suspended in 1779.

[38] Construction of the chapel, overseen by a master builder Schledermann, began in 1919 and was completed in 1924, built in a Byzantine Revival style, with a Roman inspiration.

Built as an extension of the northwestern weaponporch, which then ceased to exist as an independent building, the chapel is cruciform with grey walls and a domed roof.

The coffins were designed by Kaare and Naur Klint, made from Norwegian marble, and have a stylized Dannebrog covering the lid and sides.

Following Frederik IX's death in 1972, his coffin was placed in the chapel, draped with his Royal Standard, guarded by three silver lions from the Danish Crown Regalia, and flanked by a pair of candelabra in the shape of anchors.

Since the Reformation, St Bridget's chapel has mainly been used to store various items of church inventory from Catholic times, no longer needed in the Lutheran era.

[40] Queen Margrethe II has chosen St Birgitte's Chapel as the future burial site for herself with a sarcophagus created by artist Bjørn Nørgaard.

A meeting was held in May of the same year, involving the municipality, the parochial church council, the National Museum of Denmark, and a foundation for building and landscaping culture.

The gravestone was cut from Greenlandic granite by sculptor Erik Heide, though the grave was not sealed permanently until the burial of Queen Ingrid in 2000.

The new theory is that the sign on the pier refers to Margareta Hasbjörnsdatter, who was also known as Estrid and who married Harald III Hen, the son of Sweyn Estridsen.