Despite all setbacks, four-year construction period was unprecedented for a large palace; contemporaries and modern historians agree that Brenna proved himself a capable project manager. In addition to Saint Michael's Castle, he was still responsible for works performed at Gatchina, Pavlovsk, Petergof and Tsarskoye Selo; he managed hundreds of suppliers and contractors, hired European artists, squeezed discounts out of merchants, arranged geological expedition scouting for proper granite deposits. Unlike Cameron, Brenna never hesitated to assign less-than-competent artists to "fill the void" and make the schedule; he focused on the whole picture and did not seek perfection in detail.