In this paper we present the steps followed in a project called DigitArq that aimed at building a centralised repository for archival finding aids. At the O’Porto’s District Archive, finding aids existed in several different formats and media. Migration was used to convert all the finding aids into a single normalised format based on an international standard – EAD/XML. After migration, archival management software was developed to maintain the collected information and assist archivists in the creation of new finding aids. Archival finding aids are described by hierarchical structures which can easily be described with XML but present interesting issues while using Relational Databases. The relational data model employed is described in detail.