Updated project metadata. A multitude of histone chaperones is required to protect histones from their biosynthesis to DNA deposition. They cooperate through the formation of co-chaperone complexes, but the crosstalk between nucleosome assembly pathways is unclear. Using explorative interactomics approaches, we map the organization of the histone H3-H4 chaperones network and define the interplay between histone chaperones systems. We identify and validate a panel of novel histone (PTM) dependent complexes. We show DAXX acts separately from the rest of the network, recruiting heterochromatin factors and promoting lysine 9 tri-methylated new histone H3.3 prior to deposition onto DNA. With its functionality, DAXX provides a molecular mechanism for de novo heterochromatin assembly.