Windsor Castle, RL 12685

This is the part of Tuscany to which Leonardo dedicated the majority of his works and research projects. It is thus inevitable that Leonardo possessed a thorough, direct knowledge of the places and persons of this territory. In Florence in fact, he spent long periods of his life between the 1460s and 1508. It cannot be excluded that the artist also went to Florence as a boy with his father, or that he stayed there at times during his Milanese and Roman periods, up to the time of the Medicean projects of 1515 and his departure for France in 1516.

The Lucchesia (territory of Luca), especially the areas around Montecarlo and Altopascio, is involved in the projects for deviating the Arno in the preliminary sketch of 1495 and on the maps of 1503-1504 (RL 12685, RL 12683 and Madrid Ms. II, 22v-23r). Obviously, Lucca is clearly evidenced both as an important city of art and because it was the object of a singular project for flooding the city, devised to facilitate its conquest (Ms. B, f. 64r, around 1487).
The itinerary, with measurement of the distances, that starts at Poggio a Caiano and Montale and, passing beyond Pistoia, arrives at San Gennaro and Villa Basilica, is traced in Madrid Ms. II.
On map RL 12277 Leonardo traces the course of the Serchio, while on RL 12685 he represents only the town of Barga.

This broad territory traversed by the Arno river was systematically scoured by Leonardo along the routes between Florence, Vinci, Empoli and Pisa. His reconnaissance was not limited to a route running along the two banks of the river, but was extended to the surrounding hills, all accurately indicated and measured on numerous maps (RL 12277, RL 12278, RL 12685, Madrid II: ff. 22v-23r, 53r, 2r, 15r, 16r).
This route connects without a break to those routes and geographic areas that, proceeding along the Arno from upstream to downstream, are indicated on maps RL 12278 and RL 12685 as "Florence and surroundings", "Prato-Pistoia", "Val di Pesa and Val di Greve", "Montalbano", "Valdelsa", "Volterrano and Valdera", "Pisa and surroundings".
Leonardo traversed these places innumerable times, from childhood to his second Florentine period (1508), and probably again at the time of his departure for France (1516). In addition, this territory was at the centre of his studies pertinent to the projects for deviating the Arno: for the Florence Canal (at least from 1473 to 1513) and for the Canal leading to the Stagno di Livorno (around 1503-1504).

Vinci, included in the territory of Montalbano, is the birthplace of Leonardo.
From the heights of Montalbano, between Golfolina (at the confluence of the Ombrone Pistoiese and the Arno) and Serravalle Pistoiese, Leonardo, traversing the ridge from Artimino to San Giusto and from Sant’Alluccio to Monsummano (RL 12277, RL 12685; Madrid Ms. II f. 23r with the itinerary Vinci-Serravalle-Pistoia-Poggio a Caiano and measurement of the distances to the foot of western Montalbano), observed the Val di Nievole and the Padule di Fucecchio, drawing them in the "Landscape of August 5, 1473". From this excellent observation point he also studied the Florence-Prato-Pistoia plain and the course of the Arno between Signa and Fucecchio for the Florence Canal (up to 1513). From the town of Vinci Leonardo traversed Montalbano to arrive at Pistoia, where his aunt Violante lived, or to Bacchereto, where his paternal grandmother's kiln was located, and from where he could reach Florence.
Between 1506 and 1508, on folio 9A-9r of the Codex Leicester, Leonardo wrote:
«In the great Arno valley, above Golfolina, a rock in ancient times joined with Monte Albano in the form of a very high river bank; (which) kept that river running through a gorge so that, before it poured into the sea, which was found further on at the foot of said rock, formed 2 great lakes, the first of which is the one used today by the city of Florence, as well as Prato and Pistoja; and Monte Albano followed the rest of the river bank as far as the place where Serravalle is found today […]».

During the first years of Leonardo's career, his father Ser Piero worked as notary in Pisa.
Leonardo studied the localities, watercourses and mountains in the territory of Pisa, especially during the years 1503-1504, for his project for deviating the Arno toward the Stagno di Livorno, the realisation of which was begun on August 22,1504, only to conclude in failure the following autumn. The detailed cartography of this territory is found in RL 12683 (for the southern part), in Madrid Ms. II (on f. 22v, and especially on ff. 52v-53r; with routes and calculations on folios 1r, 1v, 2r, 3r, 16r and landscape on folios 4r, 7v e 8r) and in the Codex Atlanticus (307r).

Geographic notes on the plain of Prato and Pistoia appear frequently in Leonardo's studies relevant to the project for the navigable canal, in the notes from 1495 found in the Codex Atlanticus (126v, 127r) in the basic maps of RL 12685 (Windsor Castle) and Madrid Ms. II (f. 23r), as well as in RL 12279 and RL 12277.
These two cities were not only important for Leonardo's formation but known to him also through family connections (his aunt Violante lived in Pistoia) and for reasons of work.
On folio 23r (Madrid Ms. II) Leonardo notes some routes with measurement of their distances from Prato to Pistoia, in the direction of Collodi.
The Pistoian Apennines are mentioned only for the sources of the Reno on map RL 12277, at the boundary with Emilia.

This zone extends as far as the territory of Montalbano and the water basin of Vinci in relation to the Padule di Fucecchio, into which there also flowed the Vincio, the torrent of Vinci. Leonardo had thus been familiar with the area since childhood. The drawing of August 5, 1473 represents a view of the Val di Nievole and the Padule di Fucecchio seen from Montalbano above Vinci, and not a landscape in the Valdarno as has sometimes been thought.
All of the main localities in the area are represented on map RL 12685 (Windsor Castle) and in Madrid Ms. II, ff. 22v-23r, which show the two itineraries that also involve the Montalbano area and the plain of Prato and Pistoia: Vinci - Serravalle - Poggio a Caiano and Prato - Villa Basilica. On many other folios, Leonardo studied this territory for the deviation of the Arno into a canal that was to arrive at Val di Nievole through Prato, Pistoia and Serravalle.