Human nature is difficult to predict, as can be seen in the siege of Calais, a city in northern France.
When Calais was besieged by Edward III of England in 1346, the governor of the city turned out 1,700 men, women, and children who did not possess a sufficient supply of provisions to last several months. Edward kindly gave them a plentiful repast, and, before allowing them to pass through his ranks into freedom, gave two pieces of silver to each person.
In 1347, when matters were becoming desperate in Calais, 500 more were expelled from the city. However, this time Edward refused to allow these unfortunate people to pass, and they all starved to death between the walls and the English camp.
After a year's siege, Calais was eventually taken.
人性變化難測，這一點，可見於法國北方城市加來的一場攻守戰。
一三四六年，英王愛德華三世圍攻加來。加來長官把一千七百人驅逐出城，不分男女老幼，因為這些人沒有足夠幾個月的糧食。愛德華待之以仁，給他們一頓飽餐，還每人送兩枚銀幣，然後放他們從軍隊之中走過，自由離去。
一三四七年，加來城內情況危急，又有五百人被逐出。但是，愛德華這一次卻不放他們過去。五百可憐人困在城牆和英軍陣營之間，全部餓死。
加來苦守一年，終於被英軍攻下。