Khadijah bint Khowayled

At the age of 25 the Prophet was considered an experienced trader and started working for a successful business woman named Khadijah bint Khowayled. He never hesitated about working for a woman and treated her with respect and devotion. He led her caravan to Al Sham (Syria, Lebanon and Jordan) and always returned with profit therefore he was considered a well-established merchant.

Prophet Mohammed PBUH had a cheerful face and was flexible in all his dealings, even during times of disagreement and this cheerfulness is one major requirement for success in business.

Khadijah bint Khowayled was widowed twice and rejected several marriage proposals by the elite of Quraysh who were attracted to her beauty and wealth. She wanted an honest dedicated man and she saw all these characteristics in Mohammed PBUH although he was 15 years younger than her. She was deeply impressed by his incomparable kindness, honesty, and cheerfulness, and so she asked her friend to ask him if he would consider marrying her. The Prophet thought very highly of Khadijah and believed marrying her would be wonderful so he officially proposed to her and she accepted.

Their marriage lasted 25 years: 15 years prior to the prophetic call and 10 years after the prophetic call. Moreover, they had six children: four girls (Zeinab, Roqayia, Om-Kulthom, Fatimah) and two boys that died at birth (Al-Kasem and Abdulla).

The Prophet and Khadijah loved eachother dearly and always supported one another.

Khadijah stood by the Prophet's side during the prophetic call and was the first lady to convert to Islam. She stood by his side and was always supportive when Quraysh gave the Prophet a hard time. That's one of the reasons why God intended for Mohammed to marry an older wiser woman to stand by his side and lift his spirits when the times were tough.

After Khadijah's death the Prophet still thaught about her and every time he heard a knock at the door similar to that of Khadijah, he used to wish that the visitor be her sister Hala because he liked everything that reminded him of her.

Source:
http://www.amrkhaled.net