Sakyamuni (noble sage of the Sakya race) Gautama (the surname of Prince Siddhatta) was a Bodhisatta (one in his final birth before becoming a Buddha) before being born in Lumbini (birth place of Prince Siddhatta). Why did He marry Yasodhara (given name of Prince Siddhatta’s wife)? He is supposed not to have lust anymore. After getting married and fathering a child, He left His family and made them so sad. He is supposed not to hurt peoples’ feelings. If you say this is due to kamma, I would like to state that He was a Bodhisatta before He became the Buddha. Why did the Bodhisatta leave His family and make them feel so sad?
Remember, as a Bodhisatta, Prince Siddhatta was not perfect yet. He did have sensual desires – He became free of these only in the final moments before His enlightenment. He married to please His father and the society that required a prince should marry to produce heirs for the throne. When He left His wife and son, it was not an easy decision for Him at all.
He loved them both very much. He had to make that supreme sacrifice because He realised that He had to find the answer to the question of eternal happiness for humanity. It is like a man who decides to give up his family for some time to study medicine and become a doctor.
Such a person makes a great sacrifice, and the family also makes a sacrifice while he is studying. However, when he graduates and becomes a doctor, the family enjoys his success and at the same time he is useful to others.
The Buddha is like that doctor. After His enlightenment, He helped His family to gain supreme happiness - something greater than the temporary comfort they would have got if He had simply become king. It can be seen that because He turned away from His family for a short time, millions of beings follow Him today. Would that have happened if He had become a king? Sacrifices have to be made if greatness is to be achieved.