DARIAH-EU is the European research infrastructure for the arts and humanities. In 2016 it was recognised as an ERIC5 and it comprises 17 Members and several Cooperating Partners in eight non-member countries. The activities of DARIAH comprise four main strands, namely: 1. training and education; 2. resources, tools and methods made available by and for the research community; 3. policy and advocacy support (on topics such as open science); and finally, 4. a growing transnational community of researchers. This paper will focus on the fourth aspect and aims at exploring the case study of the DARIAH-EU Working Groups (henceforth WG) as a model in which research communities organize themselves, given the boundaries and the assets provided by a research infrastructure such as DARIAH. The DARIAH-EU WG are transnational, grass-rooted, self-organized, collaborative groups which have their roots in existing communities of practice. They form the heart of the DARIAH-ERIC community, but at the same time they maintain the existing ties with the (national and local) institutions where the WG members are based. The creation of new DARIAH WGs follows the need of communities to foster innovative scholarly practices and to provide the infrastructure to support them. In turn, participation in existing WGs is a means to consolidate infrastructure and scholarship in certain areas of research, and to create or reinforce the network of expertise inside DARIAH. The WG level enables an organizational structure which is not just flexible and dynamic, but also driven by feedback and as such it helps DARIAH to be sustainable. Furthermore the value of the working groups lies in the fact they allow a better alignment between research institutions functioning on a national basis (universities, data centers, data archives, libraries, archives, projects etc...) and the research interests that emerge in international collaborations - the WGs are therefore able to optimize their own research environment by harnessing both national and international horizons. In addition, the work of the WGs is considered so central in the development of the Research Infrastructure that in 2017 DARIAH-EU established a funding scheme to provide financial support for their activities, including travel to WG meetings, core developments such as the creation of tools, policy documents or dissemination material. This paper will therefore examine the European landscape of the DARIAH WGs, firstly by charting their evolution since 2015 and secondly, by identifying those dynamics of the research community that are the basis for successful collaboration, exchange of information and experiences. This presentation also aims to reflect on what the challenges are in the creation and maintenance of such dispersed communities, and therefore it wishes to contribute to a fruitful discussion with other national and international experiences.