Brad Pitt was married to Jennifer Aniston when he co-stared with Angelina Jolie in Mr. and Mrs. Smith. They fell in love and Pitt left Aniston for her. Pitt and Jolie ended up getting married. They had some kids and adopted some too. But off and on their marriage was a rocky one.
Jolie officially filed for divorce from Pitt on September 19, 2016. They had been separated since August of 2014. Still, when the divorce was finalized some time later, the public seemed shocked. It was if they thought it was a rumor and figured the couple were either still together in reality or that they would get back together.
Neither scenario turned out to be true. It was a nasty court battle for Pitt and Jolie which involved allogations of child abuse by Jolie. The abuse turned out to be dropped by the law but still makes for a hostile situation that remains between "Mr. and Mrs. Smith".