Europe has a long and rich tradition as a centre of research and teaching in the arts and humanities. However, the huge digital transformation that affects the arts and humanities research landscape all over the world requires that we set up sustainable research infrastructures, new and refined techniques, state-of-the-art methods and an expanded skills base. Responding to these challenges, the Digital Research Infrastructure for Arts and Humanities (DARIAH) was launched as a pan-European network and research infrastructure. After expansion and consolidation, which involved DARIAH’s inclusion in the ESFRI roadmap, DARIAH became a European Research Infrastructure Consortium (ERIC) in 2014. The Horizon 2020 funded project DESIR (DARIAH ERIC Sustainability Refined) sets out to strengthen the sustainability of DARIAH and help establish it as a reliable long-term partner within our communities. Sustaining existing digital expertise, tools, resources in Europe in the context of DESIR involves a goal-oriented set of measures in order to first, maintain, expand and develop DARIAH in its capacities as an organisation and technical research infrastructure; secondly, to engage its members further, as well as measure and increase their trust in DARIAH; thirdly, to expand the network in order to integrate new regions and communities. The DESIR consortium is composed of core DARIAH members, representatives from potential new DARIAH members and external technical experts. The sustainability of a research infrastructure is the capacity to remain operative, effective and competitive over its expected lifetime. In DESIR, this definition is translated into an evolving 6-dimensional process, divided into the following challenges: •Dissemination •Growth •Technology •Robustness •Trust •Education With our poster, we would like to show how the project helps sustaining DARIAH. Within DESIR, dissemination is the ability to communicate DARIAH’s strategy and benefits effectively within the DARIAH community and in new areas, spreading out to new communities. Through the international workshops held at Stanford University and at the Library of Congress, DARIAH has been introduced to many non-European DH scholars. These events were an important first step to foster international cooperation between US and European colleagues as well as a catalyst for ongoing collaborations in the future. A third workshop took place in Canberra at the Australian Research Data Commons in March 2019. DARIAH has currently 17 members from all over Europe. Nevertheless, efforts should be made to include as many countries as possible to bring in and scale, to a European level, even more state-of-the-art DH activities. Six candidates ready for building strong national consortia have been identified, enabling a substantial expansion of DARIAH’s country coverage. Additionally, thematic workshops are organised in each country as well as tailored training measures. DESIR widens the research infrastructure in core areas which are vital for DARIAH’s sustainability but are not yet covered by the existing set-up. As DARIAH expands across Europe, continuously enhancing and further developing the ERIC exceeds DARIAH’s internal technological capacities. Two notable results were achieved so far: firstly, the publication of a technical reference as a result of a workshop organised in October 2017 with CESSDA and CLARIN. It’s a collection of basic guidelines and references for development and maintenance of infrastructure services within DARIAH and beyond, addressing an ongoing issue for research infrastructures, namely software sustainability. Secondly, the organisation of a Code Sprint, focusing on bibliographical and citation metadata, which helped shaping DARIAH’s profile in four technology areas (visualisation, text analytic services, entity-based search and scholarly content management). Another Code sprint is expected to take place in Summer 2019. Another output is the implementation of a centralized helpdesk. This helpdesk is hosted by CLARIN-D and the solution of integration within the existing DARIAH website was the creation of a WordPress plugin. This plugin is used to connect our website with the OTRS server and allows the creation of issues easily by users unfamiliar with OTRS. Sustaining a research infrastructure involves also two important aspects: trust and education. For DARIAH, it is crucial to increase trust and confidence from its users. In DESIR we develop recommendations and strategies accordingly, targeting new cross-disciplinary communities, based on the results of a survey and interviews addressed to the scientific community, with different levels of approach - national, institutional and individual. In addition, education is a key area and the project contributes to the ongoing discussions about the role and modalities of training and education in the development, consolidation and sustainability of digital research infrastructures. We believe that investing time and efforts into training and educating users is a way of securing the social sustainability of a research infrastructure.