One account claims that the house was founded by the lady of Genova who saw a white chicken in the midst of a lot of white roosters. She became the first abbess and died 30 years later.
Donna Mira, prioress, 1203; Donna Attestina, Abbess, 1265; Donna Argentina Spinulae, Abbess, 1316.
S. Maria bought the rights to S. Stefano di Sezze in 1469. Because of problems in Tagliolo with theft, S. Stefano became the main monastery, and the order moved to Sezze (see S. Maria di Banno), at which time the Tagliolo house was taken over by monks from Genova. In 1473, the name of the combined house is changed to S. Stefano di Sezze (Sezado). In 1486, S. Maria united with S. Brigida of Genova, and the nuns return to Sezze ten years later. Finally, in 1511, S. Maria was transferred to S. Elena di Genova.
Records of a number of property sales in the late 13th c.
[1] March 28, 1203: Guglielmo and Alberto of Drodo, brothers of Rondinara, sell land to the monastery.
[2] March 28, 1232: confirmation of the sale of land to Donna Jacoba Coneffra
Documenti genovesi di Novi e Valle Scrivia, Vol. I (1909), p. 152, doc. 140
Memorie storiche di Sezze Alessandrino : l’abadia di Santa Giustina, il monastero di Santa Stefano o Santa Maria di Banno, vol. 2, p. 1505 (doc. 10)
Per la storia della diocesi di Tortona : raccolta di notizie storiche, pp. 234-5