Giuliano da Sangallo was an artist originally trained as a legnaiuolo and a sculptor, but it is especially as an architect that we remember him, particularly for his service to two generations of the Medici, from Lorenzo the Magnificent to Leo X. His late style is emblematic of the methodological questions developed by historiography around the concept of Altersstil. It was both the product of highly personal, even idiosyncratic, formal preferences and a trigger for new trends that emerged in the architecture of sixteenth-century Italy. Indeed, the erudite, seductive language displayed in the last years of his life would have a fundamental impact on subsequent generations of designers, despite the small number of projects actually completed. Different design strategies, all experimented with over the previous decades, converge in Giuliano da Sangallo’s late style, making his architectural work so distinctive and pregnant with consequences: the taste for variation in the use of architectural orders and their conceptual autonomy from the wall’s mass; the sculptural treatment of figural details, producing dense atmospheric effects; the conception of the building as a boxy, elementary volume covered with precious surfaces. In 1990, Manfredo Tafuri recognized the common ground of these different aspects in their fragmentary quality. He was commenting on Giuliano's very last projects for the completion of the church of San Lorenzo through a new, monumental facade, conceived between 1515 and 1516,a few months before Giuliano’s death and as a response to an initiative undertaken by the first Medici pope. This article will focus primarily on this group of projects, or better, of drawings, but will also analyse a significant addition, presented to the public in 2017, on the occasion of an exhibition at the Uffizi. In both their graphic modes and architectural contents, these sheets represent Sangallo’s artistic testament. Characterised by sumptuous forms – i.e., showing the free and secure ductus that one would expect from an artist in the autumn of his career – and density of references, in terms of tectonics, civic identity, and antiquarian knowledge, they constitute a final word on the possibilities of representation in architecture.