In countries and times it has been different how many wives a man can have legally. In old times there were no limitations in some countries. In Christianity a man can have one wife. In Islam a man can have up to four wives.
If a child is born between a man and his wife, this child is thought of as a legitimate (lawful) child. In contrast, a child between a man and a woman who are not married is called an illegitimate child or a bastard. However, children born out of wedlock have lost a social stigma in many western countries where common-law relationships are becoming much more common.
A man whose wife is deceased is called a widower.