Legitimacy

The word legitimacy means something which is good and right. The thing may be right because it follows the law, a religion calls it right, or it may be naturally right. People may not agree about what is right and so they may not agree what legitimacy is and the things that are legitimate.
There are different uses of the word "legitimacy."
Political legitimacy
When a government is accepted by most people, it is considered to have "legitimacy". In the past, different reasons were used to make people accept a government. In the Zhou Dynasty in China, the rulers said that they were given the "Mandate of Heaven," which means that the ruler was chosen by God. That is similar to the divine right of kings doctrine in Europe, whose kings would say that they were chosen by God.
During the time of the Enlightenment, John Locke wrote that government legitimacy came from the agreement of the people who are governed. In Western thinking, that has become the accepted meaning. Not all people must agree. Only most people must agree that the government is the best way to make laws and rule if the government has legitimacy.
Max Weber said that there are three kinds of political legitimacy:
Chismatic legitimacy is people believing that a certain person is special and is most able to be a good leader. That may be because the person is very good at talking, or many people like the person. Sometimes, people will believe that the person is powerful because of a religion or because God chose the person.
Traditional legitimacy is a government being accepted by the people because it has similarity to governments in the past. When the people are ruled in the same way for a long time, many may believe that the government is good and that changing it is bad.
Rational-legal legitimacy is a government having laws that make the rulers listen to what the people say and do what is good for the people.
Children and families
In common law, legitimacy is the status of a child who is born to parents who are legally married to each another. In the opposite, illegitimacy describes someone whose parents were not married. Such a person was called "illegitimate", which literally means "not legal" (against the law). Virtually everyone alive today has ancestors who were born illegitimately.
People's attitude towards illegitimacy has varied in different parts of the world. In the Western world, especially in countries that were very religious, it was thought to be very bad for parents to have a child if they were not married. It was thought to be a sin. Illegitimate children were often called bastards. Historically, under English law, an illegitimate child was (a child of no one) and so could not get an Inheritance from his or her parents. In older times, such children were often brought up by other people, sometimes by relatives.
Today, most people's attitude has changed, and the laws have changed so that people born to unmarried parents are not discriminated against unfairly. In the United States, people are no longer described as "illegitimate" but as "born out of wedlock" ("wedlock" means "marriage"). In the United Kingdom, the idea of illegitimacy ended by a 1991 law. Fathers now have a responsibility to their children, even those born out of wedlock. Many religions still maintain that sex outside marriage is a sin, but they no longer say that the child lives in a state of sin.
References
Civil rights
Law