Supernova remnants (SNRs) are diffuse extended sources often characterized by a rather complex morphology and a highly non-uniform distribution of ejecta. General consensus is that such a morphology reflects, on one hand, pristine structures and features of the progenitor supernova (SN) explosion and, on the other hand, the early interaction of the SN blast wave with the inhomogeneous circumstellar medium (CSM) formed in the latest stages of the progenitor evolution. Deciphering the observations of SNRs, therefore, might open the possibility to investigate the physical properties of both the interacting ejecta and the shocked CSM. This requires accurate and detailed numerical models which describe the evolution from the on-set of the SN to the full remnant development and which connect the emission properties of the remnants to their progenitor SNe. Here we show how multi-dimensional SN-SNR magnetohydrodynamic models have been very effective in deciphering observations of SNR Cassiopeia A and SN 1987A.