The transformation of social, political and administrative models all along the Mediterranean medieval cultures–Italy, French Midi, Christian Iberia–, made notaries public a powerful social agent. As part of a new cultural and laic social group, notaries acted as a bureaucratic link between the common people and the elites, allowing the access not only to writing, but also to legally valid instruments that would resist memory. Its nomination was disputed between the different authorities of the Castilian Crown –monarchy, Church and nobility–as an element of jurisdictional power. The study is focused on the notarial institution and its documentary production from mid XIIIth to mid XIVth centuries. Most of these documents come from Benedictine and Cistercian monasteries established in Asturias–San Pelayo and San Vicente of Oviedo or Santa María of Belmonte are some of them–, but also from Oviedo’s Cathedral and some relevant city councils back in medieval times. Nowadays, many of the documents that make up the corpus are still preserved in this northern region, while another important amount of them is stored at the Archivo Histórico Nacional, in Madrid. The dispersion of these documentary collections adds more difficulties to the task: in the best-case scenario, there is already a digitised version of the document–e.g. in Portal de Archivos Españoles (PARES) , also accessible at Monasterium (MOM) –; if the first option is not available, the researchers have to go where the documents are preserved to proceed with their work. The foundations of this research project were established in 1986 at the VII Congress of the Commission Internationale de Diplomatique (Sanz, 1989). From this moment on, studies about notarial documentary production and notarial institution have evolved. Research projects focusing on early stage notarial history share three common purposes: to trace the different phases in the implantation of a renewed institution, and to measure the gradual reception of the restored Roman Law and specific legislative works; to observe the transformation of documentary forms and check the increasing use of writing and written instruments; and to document the jurisdictional and political tensions for the control of notaries public. Nevertheless, the methodological approaches have evolved since then according to the needs of recent research projects. Larger documentary corpora, massive digital repositories or complex crossed queries are some of our current assets to push diplomatics–and digital diplomatics– research further (De Paermentier, 2014). To achieve those objectives, the methodology developed attended to several aspects: on a historic-diplomatic basis, we have applied a TEI-based model–following the example led by the Charters Encoding Initiative (CEI) – attending to archival data, diplomatic features and socio-political aspects. Each manuscript has its own XML document, as the corpus is constructed with approximately 400 individual documents. The three main elements of our TEI-based model are: fileDesc, contains the information related to our thesis project and research group and the archival file sheet of each document; profileDesc, contains the abstract and the diplomatic data such as the actio, redactio, traditio or the datatio; and the body, contains the transcription of the document, where the element seg identifies each part of its diplomatic structure, using attributes such as @function, @type and @subtype. This mark-up model was conceived to apply a systematic analysis of the data, in order to study the evolution of notarial documents in this early stage period. For example, the use and progressive loss of religious content in the formularies used by these first notaries public. Religious formulas can be found in the invocatio and spiritual penal clauses so, using XPath queries we have managed to: trace a chronological evolution of the invocatio in our corpus, registering the maintenance and progressive loss of this kind of formulas through a century– strong presence of invocatio formulas between 1270 and 1320 –. We have noted nine different variants of the invocatio -from its latin form In nomine Domini, amen to a more evolved romance variant En el nomne de Dios e de la Virgen Santa María sua madre, amen-; from the 142 documents that contain an invocatio formula, we have identified the most recurrent juridical actions that make use of it– mostly sales, donations and avecindamientos (i.e., a neighborhood charter) –. In this work, we have exposed a mark-up system (based on TEI and CEI) which we are currently applying to extract, on a systematic basis, data from a wide range of documentary typologies. Furthermore, it can be used on other kind of documents such as the ones produced by pontifical and royal chancelleries. As future work, a more complex strategy of data analysis will be designed and applied. Our main purpose is to build a complete characterisation of the diplomatic tenor of the documents contained in our corpus. It will serve as an experimental database to test different types of analysis on large-size corpora and to produce a long-lasting encoding model.