[1] Cardinal Rengnier was born on 17 July 1794[2] at Saint-Quentin-les Beaurepaire in the region of Cambrai, France.

His parents were François Régnier and Renée Périgois.

He was consecrated bishop of the Diocese of Angoulême by his predecessor Cardinal Pierre Giraud on 22 July 1842, and succeeded him as archbishop of the Cambrai on 30 September 1850.

Pope Pius IX created him as the Cardinal-Priest of Santissima Trinità dei Monti on 22 December 1873.

He died on 3 January 1881 and was buried at the Cathedral of Cambrai.