This 2023 workshop concentrates on the presentation and discussion of recent breakthroughs in the field from high-resolution space imaging (JWST, HST) and ground-based spectroscopy from the optical to the radio/submillimeter to the X-ray. The axes of the discussion will be :

- Cluster assembly at z~1.5-4

- Cluster and group galaxy population at z>1.5

- Early-type galaxy formation at z>1.5

- First structures at z~4-10