What is absolute primgeniture??
The oldest child succeeds the throne, REGARDLESS of gender.
What is agnatic primogeniture???
The son or the brother or the next male descendents succeed the throne. If there are no male descendents at all, then the daughter or the next female descendent is chosen to succeed the throne.
What is an illegitimate child???
A child born to people who are not married (An example of this, is Marie Antonette who had an illegitimate child with Count Axel von Fersen, a Swedish diplomat, not Louis XVI). As a result, these children still inherit the throne under the name of the parent whose raise the child.
What is Coronation???
The act and celebration around placing a crown upon the head of the next successor. It symbolizes the passing of the monarchy and the succession of the king or queen.