The Caliphate in Southern France
The Arabs, under Al-Samh ibn Malik, governor-general of al-Andalus, swept up the Iberian peninsula and, by 719 overran Septimania; al-Samh set up a capital at Arbuna [or Narbonne as we know it].
He offered the largely Arianist Christian inhabitants generous terms and quickly pacified the other cities of Alet and Béziers, Agde, Lodève, Maguelonne and Nîmes.
Following the conquest, al-Andalus was divided into administrative areas, roughly corresponding to Andalusia, Galicia-Lusitania, Castile, Léon, Aragon-Catalonia, and Septimania.
With Arbuna secure it's port enabled Arab mariners to become masters of the Western Mediterranean.
By 721 he was reinforced and ready to lay siege to Toulouse, a possession that would open up bordering Aquitaine to him on the same terms as Septimania. But his plans were thwarted in the disastrous Battle of Toulouse taking large losses. al-Samh was so seriously wounded that he soon died at Arbuna.
Arab forces, based in Arbuna and easily resupplied by sea, struck again in the 720s, conquering Carcassonne on the north-western fringes of Septimania and penetrating eastwards as far as Autun.
In 731, the Berber lord of the region of Cerdagne, Uthman ibn Naissa, revolted against Cordova, but the rebel lord was defeated and killed by Abd al-Rahman Al Ghafiqi in alliance with Duke of Aquitaine Odo the Great, opening Aquitaine to the Umayyads.
The Arab threat on his southern borders brought Charles Martel into the conflict, Abd al-Rahman Al Ghafiqi was defeated by Charles "The Hammer" Martel at the battle of Poitiers in 732.
After capturing Bordeaux Charles Martel directed his attention to Septimania and Provence. While his reasons for leading a military expedition south are uncertain, it seems that he wanted to seal his newly secured grip on Burgundy, now threatened by Umayyad occupation of several cities lying in the lower Rhone.
Maybe it provided the excuse he needed to intervene in this territory ruled by Gothic and Roman law, far off from the Frankish centre in the north of Gaul. In 737 he went on to attack Arbuna/Narbonne, but the city held firm, defended by its Goths and Jews under the command of its governor Yusuf, Abd al-Rahman's heir.
Charles had to go back north without subduing Arbuna, leaving behind a trail of destroyed cities, i.e. Avignon, Nîmes and other Septimanian fortresses.
"France" wasn't a country at the time, it was a collection of separate states that spent most of their time fighting each other.
This gave the Moors an opportunities to work around the borders.
After the death of Charles Martel in 751 his successor, Pippin, headed south to Septimania. Gothic counts of Nîmes, Melguelh, Agde and Béziers refused allegiance to the emir at Cordova and declared their loyalty to Pippin.
The allies then besieged Arbuna but, the strongly Gothic Narbonne under Muslim rule resisted the Carolingian thrust. Attacks on the rearguard by a Basque army led by the Aquitanian duke Waifer didn't make things easy to Pippin.
In 754 there was an anti-Frank reaction, led by Ermeniard. The uprising was successful and, with re-inforcements under Abd al-Rahman, forced the Franks out of Septimania.
Pippin turned his attention to Aquitaine and it's Duke, Waifer, besieging Toulouse in 765. Pippin's death in 768 saw the kingdom partitioned between his sons Carolman and Charles.
The Carolignian Period
This left Carolman in an enviable position, with unrest at home and potential war with his brother, he was forced into a peace with Abd al-Rahman. Aquitaine was now firmly in the Caliphate's camp and it's nobles adopted many Islamic practices.
The fratricidal conflict never took place as Carolman died in 771. Charles now ruled the entire Frankish kingdom. In 773 Charles was called upon by the Pope to help against the Langobards who were trying to unite Italy. They had conquered Ravenna, ostensibly a vassal of the Pope. His invasion of Italy and capture of Pavia culminated with the forced abdication of the Langobard King. Northern Italy was absorbed into Charles' realm whilst the south was left as small Langobard states. The Pope was confirmed in his Lands, the Patrimony of St.Peter.
Charlemagne was already committed to a conflict with the Saxon tribes of Northern Germany and this proved to be a drain on his manpower with their consant revolts. The Slavs of Bohemia and Moravia and then the Avars of the Hungarian Steppes came into conflict with Charlemagne as he conquered their lands one by one.
Abd al-Rahman, from 756 Caliph, had replaced the rebellious nobles in Septimania, these found refuge at the Carolignian court. It was their influence that brought Charles, later known as Charlemagne, into conflict with the Caliphate and their allies Aquitaine in 781. Charlemagne was occupied elsewhere and without his leadership the Franks were easily defeated outside Bordeaux. Uneasy truces interspersed with periods of conflict became the pattern for the next 25 years neither side gaining an advantage.
Charlemagne was crowned Holy Roman Emperor in 800. In 806 he finally was able to personally command troops against the Caliphate and the last eight years of his life was spent campaigning in Aquitaine and Septimania. Toulouse was taken and lost three times but Charlemagne was unable to bring the Moors to a decisive battle.
Post Charlemagne
When Charlemagne died in 814 the Empire was split up between his sons. Supposedly the Empire remained united under Louis the Pious but in reality lands were ruled by his sons who were in constant conflict with each other. First Al Hakam and then Abd al-Rahman II, successors of Abd al-Rahman I, were drawn in as allies of one faction or the other.
In Southern Italy, the Aghlabids of Tunisia struck at the Byzantine island of Sicily [Balarm to the Aghlabids], decicively defeating the Byzantines and penning them up in Syracuse and Palermo. However, the death of the Aghlabid commander, Asad ibn al-Furat, left the army weak, vulnerable to counter attack. By 828 the Aghlabid army was close to defeat and in retreat to the south coast. At this time re-inforcements arrived, a volunteer force from the Caliphate, including Christian vassals from the newly subjugated Asturian lands of northern Spain. The fresh troops proved decicive and the Byzantines were defeated. Palemo was unable to hold as it had been denuded of troops, Syracuse held out until it's conquest in 978.
By 950 the so called "Holy Roman Empire" was split into five Kingdoms [Francia, Burgundy or Arles, Upper and Lower Lotharingia and Germany] and the Eastern Marches. Further east the Polish Slavs were forming proto-states and Magyar tribes were forming their own nation on the Danubian steppes.
The Eastern Empire was in a state of flux, Venice and Napoli were virtually independent but the Byzantines were resurgent in the Middle East and turning their eyes back towards their old territories in the West.
The Lombard states of Southern Italy were fighting amongst themselves and drawing in mercenaries from the Aghlabids and their Zirid successors. By 1050 the Zirids were in control of Tunisia, eastern Algeria, Sicily and Sardinia.
In addition they had gained footholds in Southern Italy.
Francia had created a new Duchy to placate the Norse invaders raiding up the Seine, this had successfully re-directed their attacks towards Southern England, conquered by 970, and brought them into conflict with the "first generation" lands of the Danelaw.
The outlying areas of Francia gradually became more independent. This was a general tendency within the Carolignian successor states; Provence and Savoy gradually evolved in the Kingdom of Arles along with the Genoese Republic, Upper Lotharingia found the Habsburg family becoming stronger, Germany, however, had always seemed to be a federation of small states held together by the threat of the Pagan Slavs to the east.
A series of Crusades against the Slavs established new German principalities in the East but also motivated the Slavs to unite and for the leader, Boleslav, to approach the Pope in 1100 for a crown in exchange for conversion to Christianity. When this was granted the internal tension within Germany emerged as Civil War in 1130.
Although no longer sanctioned by the Papacy, German colonists formed a new Duchy, Brandenburg, by escapees from the conflict for the Crown of Germany. The German economy and influence abroad would take decades to recover.
The second quarter of the 12th Century saw a period of conquest for the Norman Duchy. After the Eastern Kingdoms were absorbed in 1110, the campaign of 1130 saw the conquest of the Viking Kingdom of Jorvik along with their allies in Dublin. The Kingdoms of Strathclyde and Alba both accepted the suzerainty of Guilliame II in 1132 and both provided men for Guilliame's latest war against Francia.
Guilliame was allied with Botho of Burgundy. Phillipe of Francia had alienated his nobility to both east and west. In 1090 the far western, coastal, provinces of Francia had allied with the Duchy of Brittany and sought the protection of the Caliphate. Unable to raise sufficient opposition to the potential of the Caliphate and it's allies, Francia had no choice but to accept this as a fait accompli. Effective Royal control was now limited to the central areas of Francia and Phillipe had demonstrated the effective weakness of his nation.
Both of the Allies pushed for Paris and, despite their very real weakness in numbers, Paris was not taken. The men of Francia were able to hold out against all odds for nearly ten years. Bourbon, however, accepted a truce in 1143, the same year Phillipe died. French lands were ceded to both allies but the Kingdom survived although France and Bourbon were now equals, disputing power within the Kingdom. The remaining lands of the old Kindom of Francia in theory owed allegiance to the new Kingdom of France.
Rather than allow his troops to disband and become the marauding bandits usually found at the end of a war, Guilliame shipped them to Dublin and used them against the clans of the east, awarding lands to the leaders of his army as a way of retaining their loyalty and gaining vassals.