Recent research on the al-Qānūn al-Muqqadas, an 11th-century Arabic version of the Iberian canon law code, has shed considerable light on the position of Christians living under Islamic rule in al-Andalus, and particularly the ways in which their developing legal traditions were shaped by the experience of interacting with Islamic juridical systems. This paper builds on this research by placing these canon law texts in conversation with extant documentary sources written by Arabised Iberian Christians, which tend to deal with aspects of civil law in practice and the regulation of civil disputes. Although many of these texts were produced by Arabised Christians living under Castilian or Aragonese rule, they point to an older Christian Arabic notarial culture that drew heavily from mālikī formularies and offer considerable clues about the ways in which Andalusi Christians developed their own Christianised fiqh tradition under Islamic rule, which in turn endured in some communities long after Christian conquest. The paper will explore the opportunities provided by these documentary sources for understanding the development of legal practices of Christians under Islamic rule, and in turn, the implications for the status and political identities of these Christian communities in the moment of transition from Muslim to Christian rule.