This dissertation carefully reviews the historical sources for Christian initiation in Spain before 711. During this period, Spanish baptismal rites underwent dynamic change, a process that is followed in light of several main features of initiation rites. It is argued that it is best to avoid attempting to synthesize the historical material from this period with the baptismal rites in the later Mozarabic liturgical books, so as to critically and accurately consider this period on its own terms. Revisiting the data in this way opens up questions that seem not to have been considered. It is generally assumed that the post-baptismal chrismation in Spanish baptismal rites is equivalent to "confirmation," a distinctly Roman practice at the time. This inaccuracy leads to historical approaches that then attempt to interpret the Spanish tradition in terms of an anachronistic perspective. Similarly, the universal consensus about the "origin" of the distinctly Spanish practice of single immersion is based on an uncritical reading of the historical sources that present that very explanation. When analyzed carefully, however, it does not seem to be quite so certain, and it is argued here that a presumed pre-sixth-century practice of triple immersion in Spain is not necessarily warranted. Not only the rites, but also the interpretation of baptism in this period is surveyed. Spanish authors' rich range of interpretive motifs include a combination of regeneration language (both as rebirth and as recreation) with a Paschal context, and a seeming preference for Johannine language, all in a way that presents Paschal baptism as having a much wider range of meaning than Romans 6.