Before Joan was born, England and France fought over French territory. The conflict was called The Hundred Years War. England controlled part of southwestern France - called Aquitaine. France wanted to reclaim its own land. But England had controlled Aquitaine since the twelfth century. The English had no intention of giving it up.
By the time Joan was 8 years old, England also controlled parts of northwestern France. The battle at Agincourt was particularly costly for the French people. Suffering defeat, France signed a terrible peace agreement. The treaty with England (called the Treaty of Troyes) provided that the English king (Henry V) would become king of France after Charles VI (the contemporary French king) had died.
The "Madness of Charles VI," (this link takes you to the medieval painting at the BNF in Paris) depicts Charles crossing the forest of LeMans in a battle against Pierre de Craon. The story is from the 15th century chronicler, Jean Froissart, who was a contemporary of Charles VI. The king, who is wielding his sword, somehow thinks members of his own forces are his enemies - and attacks them. Well-known at the time, the king was "feeble-minded." (Is it hard to wonder how he came to agree to the Treaty of Troyes?)
Were the losses of French land and the disastrous treaty subjects of conversation in the D'Arc household? Those facts would be helpful to know as we piece together the evidence regarding Joan's visions and voices.