Rizpah (Hebrew: רִצְפָּה) was the concubine of King Saul of Israel and the mother of Armoni and Mephibosheth. She was the daughter of Aiah.
Abner's defection to David
After the deaths of Saul and his sons Jonathan, Abinadab, and Malchi-shua, Abner made one of Saul's remaining sons Ish-bosheth King of Israel. Meanwhile, David was anointed King of Judah.
One day, Ish-bosheth accused Abner of having an affair with Rizpah and threatening his hold on the throne. Abner then scolded Ish-bosheth for accusing him of disloyalty and defected to David's cause.
After Abner's defection, Ish-bosheth's commanders Baanah and Rechab betrayed and murdered Ish-bosheth. David responded by having the treacherous duo executed and became the sole King of Israel.
Execution of her sons
Israel was struck by a three year famine, and when David asked God for its cause, God told David that it was due to Saul's slaughter of Gibeonites:
It is because of Saul and his bloody house, because he put the Gibeonites to death (2 Samuel 21:1 (AMP)). David asked the Gibeonites about what will appease them, and the Gibeonite demanded the death of seven of Saul's remaining male descendants.
David acceded to the demands of the Gibeonites and gathered Rizpah's two sons Armoni and Mephibosheth and Merab's five sons and handed them over to the Gibeonites. The Gibeonites then executed them and placed them on display.
Rizpah then camped by the bodies of her dead sons and protected them from any animal that sought to eat them.
David learned of Rizpah's actions and had the bones of Saul and his sons, including Armoni and Mephibosheth, buried in the tomb of Saul's father Kish.