In 1218 the Dominicans established themselves in Bologna. In 1219, with the help of Cardinal Ugolino they obtained the church of San Nicolò delle Vigne despite the opposition of the wealthy Loderingo degli Andalò, who owned the land on which the church was built. Diana was Loderingo's sister. Reportedly she lived a worldly life until, inspired by Reginald of Bologna, she entered the Dominican convent at Ronzano, despite the violent reproach of her family. She was once even forcibly removed from the convent, but returned.
In 1221 Diana met Dominic of Osma when he visited Bologna. She made her vow of virginity to him and asked him to help her found a house for nuns on the model of Notre-Dame de Prouille. Dominic agreed and left behind four Dominican priests to oversee the foundation: Paul of Hungary, Guala of Brescia, Ventura of Verona, and Rudolph of Faenza. In 1222 Diana began a correspondence with Dominic's deputy, Jordan of Saxony, and they became close friends. Despite the continued violent opposition of her family, Jordan convinced them to donate land for the foundation of the convent of Saint Agnes. On 13 May 1223 the convent came into being. Diana was its first superior until her death three years later. The date of her beatification by Pope Leo XIII is given as either 8 August 1888 or 24 December 1891, the same day as that of her fellow Dominicans Cecilia Cesarini and Amata. Her feast day is either the June 8, 9, or 10.
- Western Dominican Province: The Dominican Year, gives 1891 as date of beatification and 8 June as feast day
- Beata Diana degli Andalò, Vergine at Santi Beati
- Georges, Norbert. Blessed Diana and Blessed Jordan of the Order of Preachers. Somerset, Ohio: Rosary Press, 1933.