This thesis seeks to trace the unique journey of Cater in a da Siena (1347- 1380) from a venerator of saints to a venerated saint. In doing so, the thesis presents a detailed case study of the importance of the cult of saints in medieval Europe. In order to do this, the thesis looks first at Caterina's relationship with the cult of saints through her veneration of Paul, Mary Magdalen and the Virgin Mary. This allows for a close case study of Caterina as a venerator through an examination of her own testimony in the Letters, Dialogo and her Prayers. The second section focuses on the creation of her own cult by Raimondo da Capua (1330-1399) and Tommaso Caffarini (1350- 1434). This section examines particular events and qualities such as Caterina's mystical death and her reception of the stigmata. These events were included by Raimondo and Caffarini in their hagiographies of the saint: Legenda Jvfaior, the Leggenda Minore and the Libellus. The final section explores Caterina's role as a venerated saint by examining the lives ofChiara Gambacorta (1362-1420), Giovanni Dominici (1356-1419) and Lucia Brocadelli da Narni (1476- 1544). Each life reveals a particular connection that led these venerators to Saint Caterina