The spatial compartmentalization of the genome through phase separation has emerged as a key mechanism in controlling genetic output. This talk explores the life cycle of Polycomb condensates—from molecular birth to functional impact. I will first detail the nucleation of these assemblies, identifying the number of proteins required for initiation through single-molecule imaging. I will then demonstrate how the resulting condensate landscape is intrinsically linked to the epigenetic memory marker H3K27me3. To conclude, I will present live-cell single-molecule tracking data that reveals how the condensed state alters the search and binding kinetics of nuclear factors. Ultimately, I aim to illustrate how the interplay between molecular biophysics and nuclear architecture organizes epigenetic information in the nucleus.