The following excerpt is taken from Mariam Rosser-Owen, Islamic Arts from Spain (London: V&A Publishing, 2010), p. 79-82:

“It was at Toledo during the thirteenth century that Mudejar architecture first crystallised. Toledo was the seat of the Spanish Church and one of the capitals of Castile, whose peripatetic kings spent much time in Seville, after its conquest in 1248, as they did here. Toledo is also the city which has come to be most associated with the idea of convivencia between Iberia’s three faiths, especially during the relatively mulitcultural reign of Alfonso X (r. 1252-84).
Toledo had been absorbed into Castile in 1085, and had therefore had a Mudejar community for about 150 years by Alfonso’s time, but during the early thirteenth century, new Islamic styles began to be imported from the Almohad territory which Castile was then conquering. This was the great century for Toledan Mudejar, seen especially in its churches.

Arabic inscriptions were characteristic of the Mudejar architecture of Toledo, but apart from these painted instances they tended to be written in the Kufic script, since the use of cursive writing in inscriptions only evolved in Islamic lands in the twelfth century, after Toledo was conquered by Castile. Toledo’s craftsmen were therefore isolated from this new development in the Islamic world, and the continued use of Kufic in Toledo comes to seem rather archaic.
It does not indicate that an inscription was carved at an early date, as it might do elsewhere: the example here probably dates from the fourteenth century, when cursive inscriptions were in full flow at the Alhambra, for example. The inscriptions continue to be legible, indicating that Arabic speakers were involved in their creation. Kufic inscriptions were frequently painted or carved on to wooden friezes, which ran below ceilings and usually contained a standard vocabulary of Arabic wishes for well being.”