Upon his accession to the Chair of St Peter, Pope Alexander VII Chigi (1655–1667) began to implement his extremely ambitious plan to transform Rome into a magnificent world capital by means of systematic, bold (and costly) urban planning. In so doing, he brought to fruition the long, slow recreation of the urban glory of Rome—the "renovatio Romae"—that had begun in the fifteenth century under the Renaissance popes. Alexander immediately commissioned large-scale architectural changes in the city, for example connecting new and existing buildings by opening up streets and piazzas. Bernini's career showed a greater focus on designing buildings (and their immediate surroundings) during this pontificate, as there were far greater opportunities.