Black’s law dictionary defines bigamy as “the condition of having two wives or two husbands at the same time”

In Illinois, bigamy is a crime whether you are the person that is married twice or you are one of the husbands and/or wives.

“A person commits bigamy when that person has a husband or wife and subsequently knowingly marries another.
(a-5) Marrying a bigamist. An unmarried person commits marrying a bigamist when that person knowingly marries another under circumstances known to him or her which would render the other person guilty of bigamy under the laws of this State.” 720 ILCS 5/11-45(a)

You never hear about bigamy cases even though they sound salacious and newsworthy.  This is because it is really easy to undo a bigamy charge…just divorce one of the husbands or wives.
“[I]t shall be an affirmative defense to bigamy and marrying a bigamist that: (1) The prior marriage was dissolved or declared invalid.” 720 ILCS 5/11-45(b)

Also, a person who marries a person who has multiple husbands or wives cannot be charged with bigamy if they believed their spouse was not married at the time.

In my experience, bigamy almost always happens when someone is married in a foreign country and then moves to the United States and “forgets” to get a divorce before remarrying.

Usually the bigamist isn’t even sure if they really were married back in the old country.

If you find out that your spouse was previously married and not divorced you can ask the court to declare the marriage invalid in lieu of asking for a divorce.

“Declaration of Invalidity – Grounds. The court shall enter its judgment declaring the invalidity of a marriage (formerly known as annulment) entered into under the following circumstances: 
…the marriage is prohibited.“  750 ILCS 5/301 

Declaring a marriage invalid is the same thing as an annulment.  An invalid marriage is essentially saying, “This marriage never existed.  Therefore, you cannot apply any of the divorce laws.”  This means no division of assets, no division of debts and no maintenance (formerly known as alimony)

So, is a marriage valid if it is the second marriage of a person with two or more husbands and wives?  Yes.  If they have a marriage certificate the marriage is valid until someone declares the marriage invalid.

What if the person with two husbands or wives divorces the first husband or wife?  What happens to the second husband and wife is there marriage good or not? In theory, it was never good.

“Parties to a marriage prohibited under subsection (a) of this Section who cohabit after removal of the impediment are lawfully married as of the date of the removal of the impediment.” 750 ILCS 5/212(b) 

So, the second marriage automatically becomes valid when the first marriage is divorced and the person still lives with the second husband and/or wife.

You can guarantee that these laws will all change as the future of relationships becomes more and more non-traditional.  Many cultures allow multiple wives.  There have been numerous movies about men falling in love with robots.  There is a popular reality TV  show about a goofy surfer dude who has multiple wives, Sister Wives.  The Sister Wives and their husband were even prosecuted which resulted in a federal judge declaring Utah laws that guard against polygamy to be unconstitutional.  Who knows what the future holds for multiple marriages in Illinois?

If you’d like to learn more about bigamy and divorce, contact my Chicago law office to schedule a free consultation with an experienced lawyer.