A setup consisting of N-heterocylic olefins (NHOs) and several simple Lewis acids (such as MgCl2 or LiCl) was employed to homopolymerize omega-pentadecalactone (PDL) and to copolymerize it with five-, six-, and seven-membered lactones (gamma-butyrolactone (GBL), delta-valerolactone (VL), and epsilon-caprolactone (CL)). Also, the copolymerization of GBL with VL and CL was investigated separately. This dual catalytic approach succeeded for the entropically driven high-temperature polymerization of PDL in course of fast, operationally simple polymerization procedures. PPDL could be generated in short reaction times to reach high conversion (85-97%), whereby the polymerization rates are significantly modulated by the metal halide cocatalyst (ranging from virtually 0 to >80% conversion after 15 min, 1% NHO loading). Application of mildly activating Lewis acids ensured that the frequently encountered excessive transesterification was reduced to yield relatively well-controlled polyester (M-n up to 40 kg/mol, D-M = 1.5-1.8). The 1:1 copolymerization of PDL and GBL-unifying two lactones with thermodynamically opposite polymerization preferences-was observed to be strongly dependent on the applied Lewis pair, with yield (15-50%) and GBL content (5-22%, by C-13 NMR) determined by the Lewis acid. Likewise, GBL/CL and GBL/VL copolymers displayed varying, catalyst-dependent compositions and were obtained as well-defined polyester (D-M = 1.1-1.2) with intermediate molecular weight (2-8 kg/mol) if a suitable cocatalyst pair was chosen. One-pot 1:1 PDL/VL copolymerization resulted in high or low PDL content, as well as virtually exclusive VL consumption, if Lewis pairs containing YCl3, ZnI2, or MgI2 were employed, with the reaction temperature a convenient tool to further manipulate the polymer structure. Finally, PDL/CL copolymers were readily formed, reaching high or quantitative conversion (M-n = 10-30 kg/mol) whereby 50% PDL content and perfectly random polymer structures were accessible. For selected copolymers the thermal properties were elucidated by DSC measurements.