Pierre was brought up by his uncle, Antoine Séguier, president and mortier in the parlement, and became master of requests in 1620. From 1621 to 1624 he was intendant of Guyenne, where he became closely allied with the duc d'Épernon. In 1624 he succeeded to his uncle's charge in the parlement, which he filled for nine years.
Pierre was brought up by his uncle, Antoine Séguier, president and mortier in the parlement, and became ma.ster of requests in 1620. From 1621 to 1624 he was intendant of Guyenne, where he became closely allied with the duc d'Épernon. In 1624 he succeeded to his uncle's charge in the parlement, which he filled for nine years