Hundred Years' War

[Furious Mental]

"Formigny and Castillion did kill any hope for the English to come back on French soil."

No, what killed English hopes of reconquest was the same thing as what killed English hopes of hanging on to Normandy and Bordeaux in the first place- factional conflict within the nobility which soon exploded into the Wars of the Roses and occupied English affairs for the better part of the next forty years. Neither Formigny nor Castillion crippled England militarily; in both cases it lost only a few thousand soldiers, and within a few years English nobles were raising armies numbering in the tens of thousands. But they weren't raising them to fight in France, they were raising them to fight each other. Had they wished they probably could have reopened the war in France, in fact that possibility was a consistent theme of Yorkist propaganda.

"So what do you need for a battle to be decisive if it doesn’t settle a problem?"

A battle which settles nothing in the long term is not decisive. When Formigny and Castillion were fought the outcome of the war was effectively predetermined, which is why the battles weren't decisive.

[Brenus]

“A battle which settles nothing in the long term is not decisive. When Formigny and Castillion were fought the outcome of the war was effectively predetermined, which is why the battles weren't decisive.” Ok, England lost no decisive battles, just left France because the French won small limited engagements where the English lost nothing except some towns and incomes which would have been very useful in their internal fights…

Now, we have experts saying that Germany lost the WWII because they didn’t have appropriate material (long range bombers, for ex…). So no battles were decisive because, according to your theory, the outcome of the war was predetermined by the Industrial and Military capacity…

[Furious Mental]

First of all, please do not conflate what I have said about the HYW with something someone else has said about a completely different conflict. That is just a straw man argument. Now, to address so much of what you said as is relevant:

"Ok, England lost no decisive battles, just left France because the French won small limited engagements where the English lost nothing except some towns"

Essentially. English armies were still highly professional and tactically effective, and they also had the benefit of John Talbot's leadership, who won almost all the battles and skirmishes he fought. The French made a conscious effort to avoid confronting him and concentrated on siege warfare and seizing opportunities to strike where the English were weak (which because the English nobility was so occupied with its internal struggles was pretty much everywhere). There is nothing remarkable about this. In the late 14th century du Guesclin and his successors used essentially the same strategem, and without winning any big, decisive victories over the English the French still managed to deprive them of all the land they'd won since the war started. Similarly, even though Henry V won a major battle at Agincourt most of the territory he gained was taken in the same way as it was subsequently lost; repeated sieges.

"incomes which would have been very useful in their internal fights…"

No. Territory in France was a liability to English nobles. Normandy was of dubious loyalty and had to be garrisoned by English troops even away from the frontier. In the 14th century garrisons were effectively free because they were permitted to support themselves by extorting the locals, but this policy was found to be counterproductive and thus in the 15th century Henry V and Henry VI had to pay them at considerable cost. Gascony was reliably pro-English but also economically worthless; it was precisely because of this that throughout the middle ages large numbers of Gascon men left the place to become mercenaries. As with Normandy, the cost of defending it against the French king was not justified to an English nobility more suspicious of each other. This would have been true in any case but it was especially so because the part of England whose nobles could raise the largest armies- the northern shires- was also farthest from and least concerned with continental politics, and also the place where factional conflict was sharpest. The facts speak for themselves; few English nobles even wanted any of the land which Henry V conquered, those that did have it granted to them were all absentee landlords who ignored royal requests to defend it, and all of the English nobility concentrated its efforts on building up military strength to defend their patrimonies in England. The exception to this was Calais, whose asylum and garrison were decisive for Edward IV, but this is because he was supported by the Duke of Burgundy. Any faction in the Wars of the Roses which had tried to defend all of Gascony and Normandy against the French while simultaneously waging war in England would have lost both, simple as that.

[Brenus]

“which because the English nobility was so occupied with its internal struggles” and the French were so united…

Brittany's war of succession (1341-64)
Burgundian - Orleanist/Armanac civil war

Urban and rural uprisings in France:
Parisian bourgeois revolt led by Étienne Marcel (May-June 1358).
The Jacquerie (1356-58), French rural uprising against the nobility.
Béziers' uprising (September 1381).
Agitation of the 'Tuchins' in Languedoc (1381-84).
Uprising at Rouen (Feb 1382), of the maillotins in Paris (Mar 1382).
Supression of the marchands in Paris (1383).
Cabochienne uprising (1413) in Paris: first (April), second (May).

For the English who have
English Peasants Revolt (1381).

English civil wars:
Henry Bolingbroke overthrew Richard II and established himself as Henry IV (1399), the first Lancasterian. Henry IV and his son, Prince Henry [later the V]
The Wars of the Roses (1455-85) may have been induced considerably by the English reverses at the end of the HYW.
Some will read that it was not the War of the Roses which prevent the success of the English in France, but the defeat of the English in France which lead to the War of the Roses.

“English armies were still highly professional and tactically effective” Definitively true. They knew their job, had a better habit to work together (unlike the French nobility slaughtering its own arbalesters and infantry, or disobeying orders).
What Agincourt changed was they were dead and an effective more professional (even if less glamorous) army took shape under Jean Bureau and his King Charles VII.

[Furious Mental]

Yes the French were highly disunited at times. That is essentially why the war dragged on for 115 years. Once the tables turned and the French were united while the English were divided, the war turned irreversibly in France's favour.

"Some will read that it was not the War of the Roses which prevent the success of the English in France, but the defeat of the English in France which lead to the War of the Roses."

Yes the final defeat of the English in France was one of the short term causes of the Wars of the Roses because it totally discredited Henry VI, especially among London burghers. But the long term causes of the Wars of the Roses went back decades. The disputed claim of the Lancastrian kings to the throne was the major factional dispute and this swept up and polarised the English nobility as individual nobles manouevred to use the Lancaster-York dispute to further their own particular interests and the kingmakers sought allies; often established families were trying to protect their powerbase against newly enobled men. Henry VI was too weak and unpopular to control these factional disputes and the growth of noble affinities into private armies numbering in the thousands or tens of thousands. Even though the war with France had been popular among the nobility they were simply afraid and hateful of each other to participate in it after Henry V died.