Petronilla de Grandmesnil, Countess of Leicester (c. 1145—1212) was the daughter of one of three Grandmesnil brothers, William, Ivo, or Hugh, and wife of Robert de Beaumont III, earl of Leicester, known as “Blanchmains” (d. 1190). She was buried in Leicester Abbey following her death on April 1, 1212.
The chronicler Jordan Fantosme wrote of Earl Robert and Countess Petronilla as participants in the rebellion of Henry "the Young King" against King Henry II, his father. Jordan claimed that, because of grievances against the king, Earl Robert participated in the Young King's rebellion in 1173-4, and credits Countess Petronilla for dismissive remarks about the English who were fighting for Henry II: "The English are great boasters, but poor fighters; they are better at quaffing great tankards and guzzling."[1] The countess accompanied her husband on his military campaign against those English troops, under the command of the earl of Arundel and Humphrey de Bohun. During the final showdown, she is said to have fled from the battle, only to be found in a ditch. "The earl’s wife wanted to drown herself, when Simon of Odell saw to pulling her out: ‛My lady, come away from this place, and abandon your design! War is all a question of losing and winning."[2] Her husband was also captured, the couple were briefly in joint custody and the earl's holdings were confiscated. Countess Petronilla was released before her husband, and during the earl's continued imprisonment he wrote to her asking that she discharge the bequests stated in his father's will.[3]
Countess Petronilla claimed to be the heiress of the Grandmesnil barony but the records do not record the names of her parents.[4] The countess, married in the mid-1150s, bore at least seven children: