We study the impact of cosmological expansion onto the equilibrium and dynamics of localised systems. In order to get hard results in terms of exact solutions to Einstein’s equations we first look at highly idealised cases which allow analytic solutions, like, e.g., a static solution describing two stars, held apart at fixed distance by a positive gravitational constant (we found such a novel solution). The next step is to investigating the possibility of non-static multiple black-hole cosmologies in terms of the explicit analytic construction of the corresponding initial data. It will be of interest to see how well these can approximate standard FLRW cosmologies.