The sole child of the marquis de Merteuil, Élisabeth de Belvoir inherited the title on her father’s death in 1619, at the age of fourteen. Before his death, the marquis, who as a soldier fought against the Turks under the banner of the Holy Roman Emperor at the Battle of Keresztes and subsequent campaigns, arranged for his daughter’s wedding to a German prince, but the prince was killed in 1622 at the battle of Wimpfen. The young marquise, now in charge of her own affairs for the first time, rejected her betrothed’s brother’s suit in 1624. The king, made aware of the young noblewoman’s situation by the duc de Nevers, brought her to court in order to find her a suitable husband befitting her rank.
The Belvoir family is an old lineage which includes the dukes of Bar.