To continue this ”old” thread with conditions as laid out by the OP – lets have a look at Denmark at the time.
A Denmark is mentioned in Italian writings to be around prior to 536 – the Fimbul Winter. The residence of that ”Denmark” was in Fyn the central isle of Denmark.
Post the Fimbul Winter a new center of power emerged in Sjælland the eastern isle at Lejre home of the Scyldings were great halls was built during the 500's.
In order to fortify the power the Danish Kings by 700 founded the Trade center of what became the first city Ribe, then 726 dug a canal through the central isle of Samsø to facilitate east-west crossings in that sea-area and finally 737 at the time of the death of King Theuderic IV of the Franks the southern rampart of Dannevirke is rebuilt – with the aid or knowledge of Frisians or perhaps Estonians due to the construction of oak ”boxes” filled with soil to build upon marshy ground. 737 the Saxons rejected Frankish supremacy thus inviting troubled times and of course the Danish Kings reacted to this.
As soon as the crisis evaporated Dannevirke was once again left to itself only to get a rebuild once the Franks came too close 804.
The Franks had subdued the Frisians 734 which area had been subjected to a Danish raid by King Cholchilaitus around 516/530 and king Godrey would 810 invade Frisia to demand tribute thus the area by the Danish Kings were seen as dependants which should pay tribute.
King Sigfried had a tie to the Saxon warleader Widukind as he was married to one of Sigfried daughters.
Thus in case of a Saxon defeat of Charlemagne and killing him Danish King Sigfried would have to work out some deal with the Saxons – claiming Frisia. The area to the south of Dannevirke rampart in the first map in the linked to thread marked 810 was actually a barren unsettled area ideal for a major fortification as no army could live off such lands.
When the Franks 810 conquered the land they built a fortress at Itzehoe in the area to be able to sustain an army in area.
The Viking raids in England was very much due to the current coastline of eastern England:
These waters facilitated Viking raids all out of proportion to the size of GHA.
As their nobility had a great time in England and Western Europe the Danish Kings also at times used their Army to fight the Franks and later Germans in alliance with the Slav – Obotrites, etc. only in the end deciding to conquer England.
As long as the Franks are busy getting a new King there is room for Saxon and Danish expansion.
Obotrites is in some way into the Danish Royal sphere of interest at this time as Danish coin have been found at Reric on the Baltic Coast
so a Danish Royal – Saxon alliance is very much a possible if only to protect interest's and territory.
How much the Saxons decide to advance towards the Rhine and perhaps into Thuringia isn't of the Danish Kings worry as long as he keeps his supremacy of Frisia.
A Denmark is mentioned in Italian writings to be around prior to 536 – the Fimbul Winter. The residence of that ”Denmark” was in Fyn the central isle of Denmark.
Post the Fimbul Winter a new center of power emerged in Sjælland the eastern isle at Lejre home of the Scyldings were great halls was built during the 500's.
In order to fortify the power the Danish Kings by 700 founded the Trade center of what became the first city Ribe, then 726 dug a canal through the central isle of Samsø to facilitate east-west crossings in that sea-area and finally 737 at the time of the death of King Theuderic IV of the Franks the southern rampart of Dannevirke is rebuilt – with the aid or knowledge of Frisians or perhaps Estonians due to the construction of oak ”boxes” filled with soil to build upon marshy ground. 737 the Saxons rejected Frankish supremacy thus inviting troubled times and of course the Danish Kings reacted to this.
As soon as the crisis evaporated Dannevirke was once again left to itself only to get a rebuild once the Franks came too close 804.
The Franks had subdued the Frisians 734 which area had been subjected to a Danish raid by King Cholchilaitus around 516/530 and king Godrey would 810 invade Frisia to demand tribute thus the area by the Danish Kings were seen as dependants which should pay tribute.
King Sigfried had a tie to the Saxon warleader Widukind as he was married to one of Sigfried daughters.
Thus in case of a Saxon defeat of Charlemagne and killing him Danish King Sigfried would have to work out some deal with the Saxons – claiming Frisia. The area to the south of Dannevirke rampart in the first map in the linked to thread marked 810 was actually a barren unsettled area ideal for a major fortification as no army could live off such lands.
When the Franks 810 conquered the land they built a fortress at Itzehoe in the area to be able to sustain an army in area.
The Viking raids in England was very much due to the current coastline of eastern England:
These waters facilitated Viking raids all out of proportion to the size of GHA.
As their nobility had a great time in England and Western Europe the Danish Kings also at times used their Army to fight the Franks and later Germans in alliance with the Slav – Obotrites, etc. only in the end deciding to conquer England.
As long as the Franks are busy getting a new King there is room for Saxon and Danish expansion.
Obotrites is in some way into the Danish Royal sphere of interest at this time as Danish coin have been found at Reric on the Baltic Coast
so a Danish Royal – Saxon alliance is very much a possible if only to protect interest's and territory.
How much the Saxons decide to advance towards the Rhine and perhaps into Thuringia isn't of the Danish Kings worry as long as he keeps his supremacy of Frisia.