Long before “the” English Civil War of the 1640s, England had already torn itself apart in a number of other brutal internal conflicts.
The first of these was between 1138 and 1153, when the country descended into chaos in a period known as The Anarchy; and Northamptonshire found itself right in the middle of it.
This conflict saw King Henry I’s daughter, Empress Matilda, fighting against her cousin Stephen of Blois for the English crown.
It All Began at Northampton Castle
The story of The Anarchy began right here, in Northamptonshire.
On 8 September 1131, King Henry I held a council at Northampton Castle. The king had a problem: his only legitimate son, William, had drowned in the White Ship Disaster eleven years earlier, and his second marriage had produced no children.
And while he did have a number of sons through his mistresses, none of these were “legitimate” to be named as his successor.
His solution was unprecedented: he would make his daughter, the Empress Matilda his heir.
At Northampton Castle that day, the great Barons of England renewed their oath to recognise Matilda as Henry’s successor, first sworn at Westminster in 1127.
But it this time, the oath had added significance: among those swearing allegiance was Stephen of Blois, Henry’s nephew and a man who would later break the oath spectacularly.
When Oaths Were Broken
When Henry I died unexpectedly in December 1135, everything fell apart. Matilda was in Anjou, pregnant with her third child.
On paper, the throne was waiting for her. She had done everything expected of her: produced two male heirs and secured the sworn loyalty of England’s nobles.
She had every reason to expect they would keep their word.
They did not.
Stephen of Blois raced to London and seized the throne. His brother, the Bishop of Winchester, helped by claiming (rather conveniently) that Henry had changed his mind on his deathbed and absolved everyone of their oaths.
Most Barons accepted Stephen; whether because they believed this story, because they doubted a woman could rule, or simply because they feared chaos without a king quickly in place.
Matilda was furious. She’d been named heir, produced further heirs as required, and secured sworn oaths. Now those oaths meant nothing.
By 1139, she invaded England to claim what was rightfully hers, and the country plunged into civil war.
It Was Northampton’s Fault!
There is a credible argument that Stephen of Blois might not have seized the throne had the 1131 Northampton affirmation of Matilda’s heirship been made.
By swearing the oath before Henry I of England and the leading Barons, Stephen placed himself at the very centre of royal politics. His presence marked him as a trusted inside. When the succession crisis erupted in 1135, that status helped make his claim appear plausible rather than purely opportunistic.
Ironically, Henry calling on his Barons to swear the oath helped to legitimise Stephen’s later moves. It helped expose him to the lingering doubts about a female ruler. His attendance did not simply bind him to Matilda’s cause; it may have enabled him to judge precisely when it could be displaced.
Northamptonshire’s Loyal Earl
While Barons across England switched sides repeatedly throughout the war, Simon de Senlis remained rock solid in his support for King Stephen from start to finish.
He was Earl of Northampton, and his loyalty wasn’t just about honour; it was strategic.
Historians believe Simon had calculated that if Matilda won, his earldom would likely be taken over by King David I of Scotland.
David was uncle to and a supporter of Matilda. He was not only Earl of Huntingdon; he also had a (lapsed) claim to the Earldom of Northampton, which Matilda could reinstate if she won.
Supporting Stephen was, for Simon, a matter of survival.
Even following Stephen’s capture at the Battle of Lincoln (1141) he remained loyal.
The Military Landscape
Under the Feudal System, the Barons could build stately homes or manors as they pleased, but needed royal permission to build fortified buildings.
Castles built without royal permission are sometimes called Adulterine Castles, and some of their earthworks are still visible across England to this day.
It’s hard to know for sure if there were any Adulterine Castles built in Northamptonshire. Some castles seem to have been built here at around the relevant time, but we can’t really confirm whether they had royal authority or not:
Beacon Hill Motte Castle
The mound from this castle is near the church in the centre of Wollaston village.
The lack of an associated bailey for this castle helps strengthen the claim it was built during The Anarchy: it could have been built purely as a watch point, or even as nothing more than a symbol of control for one side or the other.
As it’s hard to know exactly when it was built and dismantled, another possibility is that the castle could have been started toward the end of The Anarchy, and then abandoned unfinished when the war ended.
Lilbourne and Lilbourne Gorse
A pair of associated motte-and-bailey castles lie close to each other, in Lilbourne and Lilbourne Gorse. It’s possible they were built in opposition to each other, by the war’s two sides.
Order Restored
When King Stephen died and Henry II (Matilda’s son) took the throne, he ordered many illegal castles destroyed.
Northamptonshire returned to relative calm, and tried to look innocent.
Sources
Historic England (1992) Lilbourne motte and bailey castle and fishpond
Historic England (1992) Motte and bailey castle south of Lilbourne Gorse
Historic England (1995) Beacon Hill motte castle
West Northants Council (2025) Castle Park Heritage Part 6: Visitors to the Castle
Jack Preston 