Katherine Parr was the sixth and final wife of Henry VIII.
When Henry disposed of Katherine Howard, he was getting on a bit and he already had a legitimate male heir, as well as his two daughters, Mary and Elizabeth. So, for once in his life, he didn't need a wife to give him an heir. Or at least it wasn't his priority. Instead, he wanted a wife to make his senior years more comfortable.
He chose the twice-widowed Katherine Parr.
She was an intelligent and very pious Protestant woman from an aristocratic family and she was used to looking after elderly husbands. She was nothing like the staunchly Roman Catholic Katherine of Aragon, or the young, pleasure-loving Katherine Howard, or the fiery, ambitious Anne Boleyn. She was no challenge to Henry and had already submitted to two arranged marriages, which unfortunately were the order of the day for high-born women back then.
Katherine was a good wife by all accounts to the ailing and aging Henry. She had no biological children of her own, but she was supposed to have been a good step-mother to her husband's younger children, Edward and Elizabeth. Indeed, after Henry's eventual death, Elizabeth went to live with her. Katherine acted as Regent when Henry was away waging war in France and according to legend, her calm and effective style of leadership influenced her step-daughter's later reign.
Henry was a hard man to please and did eventually come to suspect Katherine of being too extremist in her Protestant views. Apparently a warrant had been drawn up for her arrest, but Katherine managed to talk her way out of trouble.
Henry died in 1547. Katherine married again after Henry's death and, happily, this final marriage was one of love. She became pregnant and gave birth to a daughter, but sadly she died only a few days after the birth.
Katherine is remembered for being, almost unique among the women of her time, a published author. Like Anne of Cleves, she managed to survive being married to Henry.
Read more about Katherine, or read more the six wives and this site.