Electronic communication between concentric macrocycles with wavefunctions which extend around their circumferences can lead to remarkable behavior, as illustrated by multi-walled carbon nanotubes and photosynthetic chlorophyll arrays. However it is difficult to hold one π-conjugated molecular ring inside another. Here we show that ring-in-ring complexes, consisting of a 6-porphyrin ring locked inside a 12-porphyrin ring, can be assembled by placing different metals in the two rings (zinc and aluminum). A bridging ligand with carboxylate and imidazole binding sites forms spokes between the two rings, resulting in a highly cooperative supramolecular self-assembly process. Excitation is transferred from the inner 6-ring to the outer 12-ring of this Russian doll complex within 40 ps. These complexes lead to a form of template-directed synthesis in which one nanoring promotes formation of a larger concentric homologous ring; here the effective template is an eight-component non-covalent assembly. Russian doll templating provides a new approach to amplifying the size of a covalent nanostructure.