Captured nobles in medieval times, were they always ransomed?
No they were not always ransomed. There were many ways for a captive to be taken advantage of beyond just being ransomed for short term money.
Medieval captives were entirely at the mercy of their captors. Some were held hostage for prisoner exchanges, some ransomed, some were kept indefinitely, some coerced to change objectionable opinions or sides, and of course some were just murdered. Over the centuries pretty much anything and everything was done. However, the capturing party could gain some kind of advantage, they did.
It was lucrative for Kings and important knights to be ransomed, sometimes for huge sums so this was a pretty big incentive. Ransoming was considered honorable as it helped ensure the safety of the captured party.
Richard the Lion Heart - 100,000 pounds of silver, 2 or 3 times the annual income of the crown of England at that time. King Richard was not captured in battle but was captured in Austria returning from the crusades.
Bertrand du Guesclin - 100,000 francs.
- Charles of Orleans, after the battle of Agincourt in 1415 was held by the English for 25 years. He was deemed too dangerous an enemy by King Henry V to be ransomed to France.
- The capture of Charles de Blois led to the Treaty of Westminster, (1356) then he was ransomed, and restarted the war.
Edward III signed the Treaty of Westminster on 1 March 1353, accepting Charles of Blois as Duke of Brittany if the latter undertook to pay a ransom of 300,000 crowns, and that Brittany signed a treaty of alliance "in perpetuity" with England, this alliance to be sealed by the marriage of the Montfortist claimant John of Montfort (son of the earlier John of Montfort) with Edward's daughter Mary.
- the capture of John II of France lead to the Treaty of Brétigny (1360) and then he was ransomed.
Treaty of Brétigny, (1360) Treaty between England and France that ended the first phase of the Hundred Years’ War. Marking a serious setback for the French, the treaty was signed after Edward the Black Prince defeated and captured John II of France at the Battle of Poitiers (1356). The French ceded extensive territories in northwestern France to England and agreed to ransom John at a cost of three million gold crowns, while King Edward III renounced his claim to the French throne. The treaty failed to establish a lasting peace, and the war began again in 1369.
- Harold Godwinson of England was captured by William of Normandy in Normandy before the latter invaded England in 1066. As a price for Harold's release William had Harold recant any claim to the English throne. Of course Harold who fought William at the battle of Hastings over that throne didn't find his previous vow to be a binding one.
Earwig , elder half-brother of king Edward the Confessor and claimant to the English thrown. Earwig was betrayed and captured by his one time ally and future in-law(brother Edward's wife's family), Earl Godwin. Earwig was turned over by Earl Godwin to his enemy (the Dane Cnut) who tortured and murdered him, 1017.
Most of the surviving French knights at the battle of Agincourt in 1415 were put to death by the English. King Henry's French captives outnumbered his own forces, and the English feared they were so large a number they still posed a danger to the army; so the English killed them all.
Was watching the directors cut of Kingdom of Heaven, and one of the scenes...
The movie Kingdom of Heaven pertains to the events of 1187, when Jerusalem fell to the Moslems. It contrasts Saladin the Great's behavior of sparing the inhabitants of the city of Jerusalem with the christians crusaders behavior taking the same city in 1099 where they massacred the inhabitants. In the medieval times massacres were the norm.
Siege of Jerusalem 1099
Atrocities committed against the inhabitants of cities taken by storm after a siege were normal in ancient and medieval warfare. The Crusaders had already done so at Antioch, and Fatimids had done so themselves at Taormina, at Rometta, and at Tyre. However, the massacre of the inhabitants of Jerusalem may have exceeded even these standards. Historian Michael Hull has suggested this was a matter of deliberate policy rather than simple bloodlust, to remove the "contamination of pagan superstition" (quoting Fulcher of Chartres) and to reform Jerusalem as a strictly Christian city.
Related Question:What did medieval European knights do if they were defeated in battle?