Because Isabella was the sister of the French king, Edward's government began treating some of her French connections with suspicion.
Her estates were seized or placed under tighter royal control.
Her household was reduced.
French members of her entourage were removed.
Whatever emotional relationship remained between husband and wife was now entangled with state security.
This was critical.
A medieval queen's lands were not merely spending money.
They supported her household, patronage network, dignity, and independence.
Removing them weakened her institutionally.
To Isabella, the action could be experienced simultaneously as political necessity claimed by Edward's government and as humiliation imposed by the Despenser regime.
The distinction mattered less with every passing month.
By then, Hugh Despenser the Younger had become inseparable from Isabella's complaints about her husband.
When she later explained why she would not return to England, Despenser stood near the center of her justification.
France Gave Isabella the Opening She Needed
Edward still needed to resolve the dispute with the French crown over his continental lands, because as Duke of Aquitaine he theoretically owed homage to the King of France for territories held there.
The situation was awkward.
Edward himself did not want to travel to France under conditions he considered politically risky.
A diplomatic solution emerged.
Isabella could go.
As a daughter and sister of French kings, she was well placed to negotiate.
In 1325, she crossed to France officially as Edward's queen and diplomatic representative.
At first, this was not an invasion plan.
It was diplomacy.
That distinction is essential.
Edward voluntarily allowed the woman who would eventually overthrow him to leave England because he believed she could help solve his French problem.
The decision looked reasonable.
It became disastrous.
Isabella Negotiated, but She Did Not Come Home
A settlement over Gascony required another difficulty to be solved, because Edward's heir, the young Prince Edward, could perform homage to the French king in place of his father.
The prince therefore crossed to France as well.
This gave Isabella something far more important than personal freedom.
She now possessed the heir.
Edward II remained in England.
His queen and eldest son were across the Channel.
The political balance inside the marriage changed dramatically.
Once the young Edward had performed homage, the king expected his wife and son to return.
Isabella refused.
Her refusal was not ambiguous.
She presented Hugh Despenser's influence as a barrier to her return.
As long as Despenser remained beside the king, she argued, she could not safely resume life with Edward.
A diplomatic mission had become separation.
Separation was becoming rebellion.
The Queen's French Court Became a Center of Opposition
Exiles and enemies of Edward's regime could now approach Isabella in ways that would have been dangerous in England.
Roger Mortimer was among them.
Exactly when Isabella and Mortimer became personally intimate cannot be established with the certainty later romantic accounts sometimes suggest, although contemporaries and later chroniclers widely connected them.
What can be stated more securely is that they became political allies.
That alone was explosive.
The Queen of England had joined forces with a man legally regarded by her husband's government as a traitor.
Mortimer had military and political experience.
Isabella had royal legitimacy and access to the heir.
Separately, each was dangerous.
Together, they offered an alternative center of power.
Edward understood the threat.
He demanded that Isabella return.
She did not.
He demanded his son back.
The prince remained with her.
Royal marriage had crossed into constitutional crisis.
Isabella Began Presenting Herself as a Woman Rescuing the Kingdom
No rebellion succeeds through force alone, because people need a reason to join it.
Isabella could not announce simply that she wanted to depose her husband and expect English nobles to follow.
Her public case emphasized the Despensers.
They had corrupted the king.
They had taken lands.
They had oppressed nobles.
They had driven the queen away.
The movement could therefore be presented not initially as a rebellion against monarchy but as an effort to free monarchy from evil counselors.
This was a familiar political language.
Medieval rebels often claimed they were defending the king from corrupt advisers even while raising armies against royal government.
The formulation allowed men to oppose a regime without immediately declaring themselves enemies of kingship itself.
Isabella understood its usefulness.
She was Edward's queen.
Her son was Edward's heir.
She could claim continuity while attacking the men around the king.
Only later would the question become whether Edward himself could remain king.
France Was Not a Safe Base Forever
Isabella's brother Charles IV of France was willing to support her only within limits, because open assistance for an invasion of England carried diplomatic risks.
Edward's envoys pressured the French court.
The pope became involved.
Resources were uncertain.
If Isabella remained merely a royal woman refusing to return to her husband, time could eventually work against her.
She needed soldiers.
Ships.
Money.
Allies.
That required another relationship.
Hainault provided it.
The Marriage of the Next Generation Helped Finance the Invasion
Isabella negotiated with William, Count of Hainault, and a marriage arrangement was developed between her son, Prince Edward, and Philippa of Hainault.
The match offered political and financial advantages.
Resources from the Low Countries helped make an expedition possible, while troops were recruited for the venture.
The eventual invasion force was not enormous.
Estimates vary, and medieval numbers should always be handled cautiously, although the force landing with Isabella and Mortimer was probably only in the low thousands or even fewer combatants.
This makes what happened next remarkable.
Edward II should have been able to raise much larger forces inside his own kingdom.
But armies are not created by royal title alone.
Men have to answer the summons.
Nobles have to commit.
Towns have to open gates.
Local officials have to obey.
By 1326, too many people had reasons not to.
Edward Knew an Invasion Was Possible
The king's government was not completely unaware of the threat, because preparations were made and coastal defense was considered.
Orders went out.
Officials were warned.
Loyalty was demanded.
The crown attempted to organize resistance.
Yet one problem cannot be solved by orders alone.
Edward did not know where loyalty would hold.
The same royal administration that could produce documents could not force every magnate to risk his life and estates for Hugh Despenser.
The invasion would reveal the difference between administrative obedience and political devotion.
On paper, Edward had a kingdom.
In practice, Isabella was about to discover how much of that kingdom had already withdrawn emotionally from him.
The Fleet Crossed in September 1326
The voyage itself carried substantial risk, because bad weather, interception, or an unsuccessful landing could destroy the enterprise before English supporters had time to mobilize.
Isabella was gambling not merely her political future but potentially her life and the future of her son.
If Edward captured her after an armed invasion, reconciliation would be nearly impossible.
Mortimer's fate would be even clearer.
They were crossing a threshold from which there was no safe retreat.
Once the fleet approached England, the years of negotiation and resentment became military action.
The queen who had once crossed the Channel as a royal bride was now crossing it as the center of an opposition army.
Isabella Landed in Eastern England
The force came ashore in Suffolk, near Orwell, in late September.
This location proved favorable.
Important nobles in the region were willing to support her, and local resistance did not destroy the landing.
Isabella immediately began presenting the expedition as a campaign against the Despensers and corrupt government.
Her son stood beside her.