Over the past few weeks I wrote a diary of Judith of West-Francia who happens to be one of my foremothers (I am the 38th generation). The basics were fact, the details were (mostly) fiction.
Judith was born in October 844 as the eldest child to Charles the Bald and Ermentrude of Orléans. She had one little brother: Louis the Stammerer. When she was twelve she was married off to Aethelwulf of Wessex who was then in his fifties. After his death she was married to his son Aethelbald who was then about 16. Neither the church nor her father accepted the marriage to Aethelbald and after his death the marriage was annulled. After her return home she somehow met Baldwin. It's not really clear from the records whether she was a willing elopee, but since they stayed with relatives of hers (albeit ones that wouldn't mind pestering her father), I would (and many others would) consider her a willing accomplice.
After their marriage they travelled through Europe for a while before finally going to Rome to get some help from papal quarters. Fortunately Pope Nicholas I was willing to help and after his intervention Charles finally allowed the two to be properly married which happened in Auxerre on December 13th 863. As part of Judith's dowry a piece of land in the north of Charles' realm was given to Baldwin. It is quite probable that Charles expected Baldwin to perish within months, since the area of Flandria was heavily attacked by the Vikings at that time. However, Baldwin rose to it, managed to beat the Vikings, expand his lands and properties and raise quite a big army.
Judith and Baldwin had four children: Charles (who died very young), Baldwin II (who married a daughter of Alfred of Wessex, a former stepson and brother-in-law of Judith), Rudolf of Cambrai and an unknown girl. Judith died in 870, aged 26. Baldwin died in 918.
Judith's life wasn't very long, but during her lifetime she was married to three different men, travelled a great deal, was Queen twice and turned out to be the founder (with Baldwin) of Flanders.