The XII symposium of the Einstein Telescope (ET) took place in Budapest, at the Hungarian Academy of Sciences, on the 7th - 8th of June. The ET scientific community met in Budapest for a crucial step in the long Einstein Telescope journey: the formal establishment of the ET Collaboration.

More than 400 scientists, out of more than 1200 members of the Collaboration, parti cipated in the meeting in person or remotely. The ET members discussed the status of the experiment, the technical challenges, the scientific case, and the scientific and technical progresses made by each of the ET boards. The ET Project Directorate presented the perspective from the funding agencies. Finally, the approved INFRA-DEV Horizon EU project, for supporting the preparation phase of the experiment, and the INFRA-TECH Horizon EU proposal, recently submitted to Brussels for supporting technological R&D activities, were  introduced to the whole Collaboration.  

During the meeting in Budapest,  the ET Collaboration Board (CB) was constituted, temporary chaired by Dr. H. Lueck (AEI), composed of the representatives from each of the 79 research units from 13   countries. During the first CB meeting, the ET Collaboration discussed  the recently created ET bylaws that will govern the future of the experiment and initiated procedures to set up the  required Collaboration committees.     In addition, interim ET Spokesperson (Michele Punturo, INFN) and Deputy Spokesperson (Harald Lueck) figures were identified.  

With the birth of the ET Collaboration, this  symposium marks a milestone on the long journey of the Einstein Telescope endeavour.