Nicholas V's vision of a re-built Rome was embraced by his successors, especially Sixtus IV and Alexander VI. When Julius II became Pope, he was determined that this dream would become reality and he asked artists from all over Italy to come to Rome. This is why High Renaissance culture was centered in Rome, rather than Florence.
The period which is called the High Renaissance only lasted about thirty years; it began around 1500, the year Julius II became Pope, and it didn't really survive the 1527 sack of Rome. High Renaissance art and architecture was characterized by the sort of harmony that Alberti wrote about in his treatise De re aedificatoria libri X (The Ten books of Architecture), "Everything that Nature produces is regulated by the law of harmony, and her chief concern is that everything should be perfect. Without harmony this could hardly be achieved, for the critical sympathy of the parts would be lost."
The High Renaissance was not a great period of garden making; only two important gardens were created during this period, but they both had a huge impact on the design of later gardens.
The first of these two gardens was created by Donato Bramante. In 1503, Pope Julius II commissioned him to create an enormous courtyard which would link Pope Innocent VIII's Villa Belvedere with the Vatican Palace. Bramante's Cortile del Belvedere was on a scale which hadn't been seen since Imperial Rome. Bramante transformed the small hill which the Villa Belvedere crowned into an immense terraced courtyard which was divided into three levels and totally enclosed by architecture. The largest of the three levels was at the bottom of the hill, this area was not planted, it was used for pageants, but the two upper levels featured simple geometric gardens. The dramatic staircases which linked the three levels were probably inspired by the ruins of the Sanctuary of Fortuna Primagenia in Palestrina; this was the first time that staircases had played a central role in the design of a garden. The architectural splendor of the Cortile del Belvedere set the tone for later Roman gardens. In 1551, the sculptor Bacchio Bandinelli described the Roman style when he wrote that "The things that are built should be the guide of and dominate what is planted."
