II - The fall of the Dauphin and the triumph of England
In early 1429 the English were once again calling for help. Their holdings in Normandy and Guyenne were never safe and a push deeper into the Dauphin's lands were needed.
With the support of its vassal the duke of Brabant, Philip of Burgundy was the main leader in charge of the war in France. For a long time it seemed that the English army just watched deep within its defensive positions, and the Burgundian army had to face the Dauphin's troops alone at the Battle of Bourges (1430) where the troops of the heir of France tried to cross the Loire to retake Bourges. The disaster was complete for the Dauphin, who lost 15.000 of its best soldiers for nothing, as the Burgundian army suffered minimal casualities and was still in Bourges. Meanwhile, smaller armies were conquering other key towns of France.
1430 was also the year when Brabant officially passed the control of its lands to the main branch of the Burgundian ducal family. Realising the key position of Brussel, Philip of Burgundy decided to move its capital northward in order to get a beter control of his newly aquired territories in the low countries. From there the Burgundian court became even more rich and prestigious: the prosperity of Philip's growing empire was celebrated with the creation of the Order of the Golden Fleece. Such extravagants spendings in times of war showed to all the other European monarchs the whealt of the realm of Burgundy and its quick rise to domination in western Europe.

Philip the Good with the Golden Fleece
Despite having crushed the Dauphin's army, the duke of Burgundy continued his advance in France. He secretly hoped to convince the Dauphin to surrender to him. But in 1434, a meeting took place between the remaining French forces and the king of England: despite England's victory being largely due to Philip's resolve to finish the job in France, King Henry was now considered the legitimate heir by the Dauphin. Philip has no choice, but accepted to allow Henry to enter in the cathedral of Reims to be anointed king of France.
This of course meant that Philip was now officially a vassal of Henry, but when the king of England and France orderd him to pledge allegiance (and surrender large parts of his demesne to France), Philip asked him to leave Burgundy. Henry's Victory in France was Philip's deed. He had no intention of suffering further humiliations and decided to openly defy him. And if the crown of France was now firmly into England's hands, he would rather forge his own royal title than accept him as liege.