Marie of Montpellier was born around 1182 as the daughter of William VIII, Lord of Montpellier and Eudokia Komnene, a niece of Byzantine Emperor Manuel I Komnenos. A condition of the marriage was that the firstborn child of the marriage, boy or girl, would succeed to the Lordship upon William’s death. Thus, Marie was the heiress from the moment of her birth.
Her world was turned upside down when her father repudiated her mother and married a woman named Agnes, who bore him six sons and two daughters. Eudokia became a Benedictine nun, but William’s second marriage was declared invalid, rendering all of Marie’s half-siblings illegitimate.
Marie was first married around 1192 to Viscount Raymond Geoffrey II of Marseille, but she was widowed just a year later. Her second marriage was to Count Bernard IV of Comminges in December 1197, and she was forced by her father to renounce her rights over Montpellier in favour of her half-brother William, a son of Agnes. Marie had two daughters by this marriage, Mathilde and Petronille. However, the marriage was polygamous as Bernard had two other living wives, and his marriage to Marie was finally annulled in 1201. With the annulment, she also rendered the renunciation of her rights over Montpellier void, though her father refused to recognise her as his heir. Her father died in 1202, and her half-brother took control over the city, despite Marie’s claim.
On 15 June 1204, she married for a third time to King Peter II of Aragon, and after a revolt against her half-brother, she was finally recognised as the Lady of Montpellier. From her marriage to Peter, she had two children, a daughter Sancha who died at the age of one and a son, James, who would become King James I the Conqueror. Peter II would prove to be an unfaithful husband as well, and he attempted to divorce, hoping to marry Maria of Montferrat who was Queen of Jerusalem. He did want to keep Marie’s lands, and her last years were spent fighting her husband. Pope Innocent III refused to grant Peter his divorce and Marie died in Rome on 21 April 1213 on her way back to Aragon. Their only surviving child inherited both Montpellier and Aragon.
She was buried in Sainte-Petronille Chapel in Rome, which no longer exists.