Khadija bint Khuwaylid, the wife of the Prophet, is truly known as a noble lady; she was, in the modern terminology, the First Lady of Islam.
During the Meccan phase of Islam's movement, Khadija was the main pillar of support for Prophet Muhammad (peace be upon him). She was the first one to declare her faith in Islam. Her declaration of faith was a great testimony of the Prophet's character: a wife knows her husband's outer as well as inner character. By being the first to accept person to accept Islam, Khadija demonstrated that she believed in the truthfulness of Muhammad as the Messenger of God.
The initial years of Islam's mission were very trying; the Prophet faced severe opposition from the people of Mecca. In face of this rejection, Khadija provided the moral support and boasted the morale of the Prophet. According to Muslims historians, he even used to consult and discuss with her the issues related to the Islamic movement.
Khadija whole-heartedly supported the Prophet's cause by placing her wealth at his disposal. Almighty God has praised that by addressing the Prophet: "Did We not find you in need and made your free of need?" (93:8) It was through Khadija's wealth that the Almighty made the Prophet self-sufficient in his financial needs.
Although Khadija came from a very affluent background, she did not shy from sacrificing her wealth for the cause of Islam. Not only that, she even willingly went through the difficulties of three years of social/economic embargo imposed upon Prophet Muhammad and his family, the Banu Hashim. The hardship of these three years eventually resulted in her death.
It is to her credit that the Prophet of Islam did not marry another woman as long as Khadija was alive; she was the only wife who bore children for him. The name of Prophet continued through Fatima, the daughter of the Prophet and Khadija.