Adèle de Batz de Trenquelléon

Adèle de Batz de Trenquelléon, FMI, religious name Mary of the Conception (French: Marie de la Conception), (10 June 1789 – 10 January 1828), was a religious sister and the co-founder of the Marianist Sisters with William Joseph Chaminade. The religious institute in the Roman Catholic Church was founded to serve the poor.

As a child, de Trenquelléon's desire had been to become a Carmelite, but this desire was never to materialize; she instead focused herself on serving the poor wherever and whenever she could. The congregation was founded with the intention of serving the poor and supporting the Sodalities of the Immaculate Conception that were started by William Joseph Chaminade and supported by Marie-Thérèse Charlotte de Lamourous as missionaries of Mary, thus combining certain aspects of the Carmelite charism with this impulse to balance the aspirations of the two co-founders.

The cause for her beatification was opened in the mid-1960s. On 5 June 1986, Pope John Paul II confirmed her heroic virtue and titled her as venerable. Pope Francis confirmed a miracle attributed to her intercession and approved her beatification in May 2017. Mary of the Conception de Trenquelléon was beatified in Agen on 10 June 2018, the anniversary of her birth.