Advancing FronTier Research In the Arts and hUManities (ATRIUM) will exploit and strengthen complementarities between leading European infrastructures: DARIAH, ARIADNE, CLARIN and OPERAS in order to provide vastly improved access to a rich portfolio of state-of-the-art services available to researchers across countries, languages, domains and media, building on a shared understanding and interoperability principles established in the SSHOC cluster project and other previous collaborations.Arts and Humanities is a very diverse field, covering a range of disciplines and communities of practice that have different epistemological and methodological foundations: an archaeologist and an art historian studying a Mycenaean fresco will have distinct goals and use different approaches to describing their objects of research. A literary scholar and a linguist will come to a textual corpus with radically different senses of what a corpus is and what questions can be asked of it. Yet research infrastructures in the Arts and Humanities domain must cater to a very wide range of stakeholdersand offer services that cut across discipline-specific boundaries.ATRIUM will tackle this heterogeneity within the Arts and Humanities by going deep and wide at the same time: on the one hand, ATRIUM will make a groundbreaking contribution to the consolidation and expansion of services, including data services, specifically in the field of archaeology, while, on the other hand, facilitating access to a wide array of essential text, image and sound-based services that benefit a number of other disciplines within the Arts and Humanities, and cover all phases of the research data lifecycle (creating, processing, analyzing, preserving, providing access to andreusing).