What Galaxy clusters are the most massive gravitationally-bound objects in the Universe. Millions of light-years in size and containing up to thousands of galaxies residing in massive dark matter halos, they are truly amongst the most awe-inspiring objects in the Universe. However, their alluring beauty so prominently on display in the present-day Universe belies what is likely a complex and prolonged formation history. The project aims to shed new light on how galaxy clusters formed and evolved with cosmic time and how powerfully accreting supermassive black holes at the centres of the clusters affected the cluster evolution. It will do so by making use of new comprehensive surveys of distant galaxy clusters conducted at multiple wavelengths and state-of-the-art numerical simulations. Why Galaxy clusters are the building blocks of the large scale structure of the Universe. Understanding how they formed and evolved is an important part of our endeavour to know our cosmic origins. Galaxies in clusters frequently and strongly interact compared to galaxies in the field. Galaxy clusters are, therefore, our best laboratories for studying up close the full spectrum of physical mechanisms governing galaxy evolution. We know hardly anything about the nature of supermassive black holes and how they affect and are themselves affected by the build-up of the massive galaxies and the clusters in which they reside. That there is a physical link is strongly suggested by the fact that accreting supermassive black holes are exclusively found in overdense protocluster regions of the Universe. How The project builds on new wide and deep surveys that trace the evolution of galaxy protoclusters across cosmic time. It targets galaxy-overdensities in protoclusters during the Cosmic Dawn era, when the Universe was about one billion years old, and protoclusters first emerged, and the subsequent Cosmic Noon era when clusters rapidly assembled. The effects of supermassive black holes on cluster growth are examined by targeting protoclusters containing an accreting supermassive black hole in their central massive galaxy and protoclusters that do not. The project's full potential is realised in symbiosis with computer simulations of the transformation of protoclusters, containing supermassive black holes and numerous young galaxies, to today's massive clusters of mostly dormant galaxies. SSR It is a priority of the project to engage in public outreach. The scientific questions and results of the project will be announced and disseminated on social media and news outlets. We aim to pique the curiosity and install a sense of wonder towards astronomy and science in the general public, and especially in young people. The technological discoveries of tomorrow that will help us overcome the many challenges the world is facing will come from the young and children of today who will go on and study science and engineering at university.