Michal was a daughter of Saul and wife of David. She fell in love with David soon after the young man had slain Goliath, a feat that incurred the jealousy of Saul, who thereafter kept plotting to kill him. When he found out about his daughter's feelings for David, he decided he could use this development as an opportunity to get rid of David.
He told David that he could marry Michal if he brought him a hundred Philistine foreskins. David, undoubtedly delighted with the chance to rise from shepherd boy to son-in-law to the king decided to go one ahead!
David and his men went out and killed two hundred Philistines
. He brought their foreskins and presented the full number to the king so that he might become the king's son-in-law. Then Saul gave him his daughter Michal in marriage.
(1 Samuel 18:27)
Saul's hatred for David increased after this and one day he sent men to David's house with orders to kill him. Michal, putting an idol with goat's hair in the bed as a decoy, let David down through a window to escape. Michal was given in marriage to another man, Paltiel, but David afterwards reclaimed her as his wife.
The relationship between Michal and David however wasn't the same, perhaps a result of the reality that she was just one of his wives. Things came to a head on the day when the Ark of the Covenant was brought back in great triumph. Michal was infuriated at the way David leaped and danced in celebration, thinking his behavior undignified, and she made her displeasure evident. David didn't hide his own contempt for her.
David said to Michal, "It was before the LORD , who chose me rather than your father or anyone from his house when he appointed me ruler over the LORD's people Israel-I will celebrate before the LORD . I will become even more undignified than this, and I will be humiliated in my own eyes. But by these slave girls you spoke of, I will be held in honor."
(2 Samuel 6:21-22)
Michal remained childless, thus keeping apart the races of David and Saul.