Why did Charles George Gordon remain in Khartoum despite orders to evacuate?

General Charles George Gordon remained in Khartoum despite orders to evacuate because he intended to defeat the Mahdists rather than abandon the city. Gordon believed that if he could break the power of the Mahdiyyah movement in Khartoum, he could prevent them from advancing into Egypt.21

Instead of following the British government's directive to oversee the withdrawal of Egyptian forces, Gordon established a defensive line and requested reinforcements. While some biographers have suggested that Gordon deliberately defied his government's orders to remain in the city even when evacuation was still possible, his stated motivation was to safeguard strategic interests by stopping the Mahdist forces before they could expand their reach.213