The oldest bells
Although one tradition has it that Paulino de Noya used bells to summon to prayer in the 5th century, there is no historical evidence of the use of bells until a mention by Gregory of Tours in the second half of the 6th century. Two small Mozarabic bells with inscriptions exist, and they needed to be hung up to peal: one was donated by Abbot Sansón to the Chapel of San Sebastián in 930, which is now in the Museo Arqueológico de Córdoba, and the other is in the Museo de Huelva, and dates from the first half of the 11th century and bears the name of its maker or patron, Omar ben Zakaría, carefully written in Kufic characters.
The use of bells with votive inscriptions in Muslim areas seems to point to a custom from before 711 which has lived down to the present day. While the bells mentioned above were lucky archaeological discoveries, the Laurentine bell which Archdeacon Rodrigo Gundisalvo had smelted in honour of San Lorenzo in 1085 remained in use in the Colegiata de San Isidoro de León until recently, and is now in a museum.