A subsequent agreement in 1984 between the Commission of the European Communities and the EUI laid the groundwork for establishing the Archives in Florence,[5] and the HAEU opened its doors to researchers and the public in 1986.
It also collects and preserves private papers of individuals, movements and international organizations involved in the European integration process.
It also holds private deposits and collections from individuals, organisations and associations that advocated, supported and implemented the Post-World War II European conciliation and integration process.
With the passing of the Salviati family, the estate changed hands many times in the last two hundred years and was owned by the Borghese princes, the English Vansittart, the tenor Mario Da Candia, and Gustavo Hagermann in the 19th century.
Since 2000 Villa Salviati has been the property of the Italian State and after the extensive restructuration it has been destined to host the HAEU with 11,000 linear metres of shelving created in a subterraneous deposit.
The HAEU also publishes the information and the classification schemes of the institutional holdings on the 'Archives Portal EUROPE' and it is linked to the social media Facebook, Twitter, YouTube and Flickr.
Access to all archival documents, collections and interviews preserved at the HAEU and available online or in the reading room is free of charge.
The HAEU hosts and organises in close cooperation with the EUI History Department and with external partners research seminars, workshops and conferences.