St Martin’s church, Angers, is emblematic of the problems raised in pre-12 th century history of architecture. In view of the importance of this building, it was necessary to attempt to define its dating and this study particularly focuses on its bell-tower. In addition to the conclusion resulting from the interpretation of written sources and typological criteria positioning the construction of the site at the beginning of the 11 th century, not only a significant number of 14 C dates were carried out on charcoals from the masonry structures, but also independent dating by archaeomagnetism and thermoluminescence were performed on bricks from the bell-tower. The whole results from these three different methods agree and indicate the lower level of the bell-tower was likely built in the 9 th century, disputing evidence to the theory of construction in the 11 th century of the church. Presented here are the detailed results obtained from the thermoluminescence (TL) dating analysis.