The creation of the common Hungarian Archives Portal (HAP) (www.archivportal.hu) was supported by the Ministry of Education and Culture in 2009 in the framework of the „Service Provider Archives” Project. The Ministry charged Budapest City Archives with the achievement of the project. The common portal provides up-to-date information on archives for professionals, for users and for the general public and publishes a joint database integrating the various individual archival data and digitized archival records (maps, documents, files, etc.) of the collaborative institutions. The presentation focuses on one specific function of the Common Portal: the Joint Archival Database. The aim of the project was not to create new digital content, but to integrate into one system and to publish what the collaborating institutions already had. At the moment the HAP publishes more then 1, 8 Million records and 3 Million images. The HAP has 10 different sub-databases with the same frame system by the attendance of 23 Hungarian Archives: 1. Integrated Archival Database (which unifies descriptive records on highly different types or archival files and documents, many of them connected with digital images) 2. Database of fonds and sub-fonds (basic data of the archival material) 3. Cadastral maps of the counties (with georeferenced maps and a gazetteer database) 4. Digitized documents of the Communist Party (searchable PDF format) 5. Archival publications (searchable PDF format)  6. Archontology and Name Directories. Besides the HAP includes 4 database of the Hungarian national Archives (medieval charters, plans, Urbaria et conscirpitones, Libri Regii). Each of the sub-databases (integrated database, fonds and subfonds, cadastral maps – settlements names, documents of the communist party, archival publications, archontology and name directories) has its own search engine. The unified search engine enables the simultaneous and easy search of the complete Joint Database with one click.