Danevirke 1 – Hovedvolden ("the main rampart"), Nordvolden ("the north rampart"), Østervolden ("the east rampart")
The first Danevirke was built in five stages, starting about 650, according to carbon-14 dating.
The first three stages were simple ramparts of soil, and the fourth stage was a palisade rampart with heavy timber front, built in 737.
In the final stages the timber palisade was reinforced with a heavy stone wall around the timber.
Work is said to have been started by Angantyr, and continued by Siegfried, and ended by Guðfrið according to annales in 808.

Hovedvolden: From Rejde Å (now called Rheider Au) to a small lake called Dannevirke Sø.
It was the main segment of the Danevirke.
About 2 m high and 12 m wide.

Nordvolden: From the northeastern side of Dannevirke Sø, and further north about 7 km.

Østervolden: About 3.3 km long, and protecting Schwansen.

A 900 m long submerged construction in Slien.

Danevirke 2 – Kovirke ("cow-work")/Kograben ("cow-moat" or "district moat")
Built either by Guðfrið or by Harald Bluetooth (if it is the work mentioned as newly made in the Frankish royal annals in 808, then Harald did not build it) it stretched from the Rheide Å about 7 km to a southern extension of the Schlei bay which is now a lake called Selker Noor.
Its palisade was about 3 m high, and was a little more solid than that on the first ramparts.
The bank of earth behind the palisade was about 2 m high and 7 m wide.
It had a V-shaped moat, 4 m wide and 3 m deep.

The construction period of this rampart would have been some time between 770 and 970.

Danevirke 3 – Hovedvolden/Hauptwall/"main rampart", Krumvolden/Krummwall/"curved rampart", Buevolden/Bogenwall/"bow rampart"), Dobbeltvolden/Doppelwall/"double rampart", Forbindelsesvolden ("the connecting rampart")/Margarethenwall ("Margret's rampart")
Hovedvolden was expanded, so that it was now about 5 m high and about 20 m wide.
Krumvolden was built through the Rheide Å, and overlapped with Hovedvolden.
Forbindelsesvolden closed a gap between Halvkredsvolden ("the semicircle rampart", a bank that protected Hedeby) and Hovedvolden near Dannevirke Sø.
Buevolden and Dobbeltvolden protected an important road junction.
This wall is connected to most of the building work is attributed to Harald Bluetooth.
Arild Hvitfeldt's Danmarks Riges Krønike adds a little detail to the extension of the Danevirke in that time period.
 "Then summoned (Queen) Thyra (wife of Gorm the Old) Danes from all the kingdom's regions to meet at the border and under her supervision they built a wall of earth and timber from Slien over the moors to Trene.
The Scanians received the western section from Karlegat to Trene.
Zealanders and Funen dwellers received the section east from Slien (Schlei bay) to Karlegat.
Jutlanders provided provisions to the whole army."
This would place Thyra's extension sometime before 940.
Forbindelsesvolden was attacked by the Saxons of the Ottonian dynasty in 974.

Danevirke 4 – Hovedvolden/Hauptwall/"main rampart".

Reinforcement on the Main Wall finished in 954, and a new Forbindelsevold build from 964 to 968.
Harald Bluetooth is thought to be the main constructor.

Danevirke 5 – Forbindelsesvolden, Krumvolden, and Hovedvolden
Under Canute IV of Denmark  (1080–86) Denmark was at war with the German empire.
The Danevirke was strengthened at the beginning of the 12th century: the moats were deepened and the ramparts were made higher.
A granite boulder palisade wall was built on a part of Hovedvolden.

Danevirke 6 – Hovedvolden and Thyraborg
Valdemar I fortified the rest of Hovedvolden with the famous "Valdemar-wall", a 7-m high wall of stones in mortar on a granite boulder base, propped up with buttresses and covered with tiles.
This was a large reinforcement, and doubtless deterred many who tried to send an army northwards through Jutland.
It was the last true reinforcement of the ramparts.
Later Thyraborg castle was built.

The Danevirke began to lose its purpose in the 14th century, owing both to the expense of manning it and to the development of ballistas, trebuchets, and si
Danevirke 1 – Hovedvolden ("the main rampart"), Nordvolden ("the north rampart"), Østervolden ("the east rampart")
The first Danevirke was built in five stages, starting about 650, according to carbon-14 dating. The first three stages were simple ramparts of soil, and the fourth stage was a palisade rampart with heavy timber front, built in 737. In the final stages the timber palisade was reinforced with a heavy stone wall around the timber. Work is said to have been started by Angantyr, and continued by Siegfried, and ended by Guðfrið according to annales in 808.
Hovedvolden: From Rejde Å (now called Rheider Au) to a small lake called Dannevirke Sø. It was the main segment of the Danevirke. About 2 m high and 12 m wide.
Nordvolden: From the northeastern side of Dannevirke Sø, and further north about 7 km.
Østervolden: About 3.3 km long, and protecting Schwansen.
A 900 m long submerged construction in Slien.
Danevirke 2 – Kovirke ("cow-work")/Kograben ("cow-moat" or "district moat")
Built either by Guðfrið or by Harald Bluetooth (if it is the work mentioned as newly made in the Frankish royal annals in 808, then Harald did not build it) it stretched from the Rheide Å about 7 km to a southern extension of the Schlei bay which is now a lake called Selker Noor. Its palisade was about 3 m high, and was a little more solid than that on the first ramparts. The bank of earth behind the palisade was about 2 m high and 7 m wide. It had a V-shaped moat, 4 m wide and 3 m deep.
The construction period of this rampart would have been some time between 770 and 970.
Danevirke 3 – Hovedvolden/Hauptwall/"main rampart", Krumvolden/Krummwall/"curved rampart", Buevolden/Bogenwall/"bow rampart"), Dobbeltvolden/Doppelwall/"double rampart", Forbindelsesvolden ("the connecting rampart")/Margarethenwall ("Margret's rampart")
Hovedvolden was expanded, so that it was now about 5 m high and about 20 m wide. Krumvolden was built through the Rheide Å, and overlapped with Hovedvolden. Forbindelsesvolden closed a gap between Halvkredsvolden ("the semicircle rampart", a bank that protected Hedeby) and Hovedvolden near Dannevirke Sø. Buevolden and Dobbeltvolden protected an important road junction. This wall is connected to most of the building work is attributed to Harald Bluetooth. Arild Hvitfeldt's Danmarks Riges Krønike adds a little detail to the extension of the Danevirke in that time period.  "Then summoned (Queen) Thyra (wife of Gorm the Old) Danes from all the kingdom's regions to meet at the border and under her supervision they built a wall of earth and timber from Slien over the moors to Trene. The Scanians received the western section from Karlegat to Trene. Zealanders and Funen dwellers received the section east from Slien (Schlei bay) to Karlegat. Jutlanders provided provisions to the whole army." This would place Thyra's extension sometime before 940. Forbindelsesvolden was attacked by the Saxons of the Ottonian dynasty in 974.
Danevirke 4 – Hovedvolden/Hauptwall/"main rampart".
Reinforcement on the Main Wall finished in 954, and a new Forbindelsevold build from 964 to 968. Harald Bluetooth is thought to be the main constructor.
Danevirke 5 – Forbindelsesvolden, Krumvolden, and Hovedvolden
Under Canute IV of Denmark  (1080–86) Denmark was at war with the German empire. The Danevirke was strengthened at the beginning of the 12th century: the moats were deepened and the ramparts were made higher. A granite boulder palisade wall was built on a part of Hovedvolden.
Danevirke 6 – Hovedvolden and Thyraborg
Valdemar I fortified the rest of Hovedvolden with the famous "Valdemar-wall", a 7-m high wall of stones in mortar on a granite boulder base, propped up with buttresses and covered with tiles. This was a large reinforcement, and doubtless deterred many who tried to send an army northwards through Jutland. It was the last true reinforcement of the ramparts. Later Thyraborg castle was built.
The Danevirke began to lose its purpose in the 14th century, owing both to the expense of manning it and to the development of ballistas, trebuchets, and si
Danevirke