Palazzo Benci stands in the street of the same name, in the past called "Corso degli Alberti". As reported by Vasari, it was here that Amerigo Benci kept for years the Adoration of the Magi, commissioned of Leonardo by the monastery of San Donato a Scopeto and remained unfinished in 1482.

The same Amerigo Benci, in the 1490s, had commissioned Leonardo to paint a portrait, now in the National Gallery of Art in Washington, of his daughter Ginevra, who in 1474 had married Luigi di Bernardo Nicolini and in 1475 had engaged in literary correspondence with Bernardo Bembo.

According to a tradition, the painting (or at least the lower part that had been cut off, with the hands) was long kept in Palazzo Pucci before entering the collections of the Prince of Lichtenstein. In the Codices Arundel and Atlanticus and in Ms. L, dating from around 1478 and the first years of the 16th century, Leonardo mentions among his companions a certain Giovanni di Amerigo Benci; specifically, he recalls him in some memorandums on a «book» (not more clearly specified but that could be the Codex Laurenziano De medicina veterinaria [Concerning veterinary medicine] by Giovanni Ruffo), with a «world map» and «my book and on jaspers». All interesting traces calling for further study.

«Labours of Hercules at Piero Ginori»: this memorandum by Leonardo in the Codex Atlanticus refers to Pier Francesco of the Ginori family, whose palazzo, attributed to Baccio d’Agnolo, stands in the street of the same name, between Piazza San Lorenzo and Via Guelfa. Built for Carlo Ginori around 1516-1520, the palazzo was enlarged in the late 17th century, also with the addition of a garden, and again in the early 19th century through the purchase of an adjacent building.

The Ginori family, which came from Calenzano, split into several branches in the late 15th century, some of them still existing today as the Ginori Lisci and Ginori Conti. Among its members we may recall Gabriello Ginori, who was Podestà of Milan in 1494, the year when Leonardo too was in the capital city of the Sforza duke.

In the 18th century the Ginori descendants founded the famous porcelain factory at Doccia.

On October 28, 1467 in a deed notarized by Ser Piero, we read: «actum Florentie in Populo Sancti Appolinaris, in domo habitationis mei notarii infrascripti», that is, compiled by Ser Piero at his own residence in Sant’Apollinare.

This was already, very probably, the house in which Ser Piero lived until 1480, in the Popolo di Sant’Apollinare, in Via delle Prestanze (also known as Via del Montecomune, or as Sdrucciolo della Dogana), enlarged in the 19th century by the implementation of Poggi's projects for Florence as capital of Italy, and forming the present-day Via dei Gondi. The building belonged to the Arte dei Mercatanti (or Calimala). Ser Piero had sublet it from Michele di Giorgio del Maestro Cristofano and then from Giuliano Gondi. In fact Ser Piero, in the Land Office report of 1480, specified: «I first stayed in a house owned by the Arte de’ Mercatanti […] rented for 30 florins a year. I engage to pay that rental fee to Giuliano Gondi up through next October, 1480».

In 1485 Gondi, who already owned the adjoining house, in which he lived, also bought the houses owned by the Arte dei Mercatanti. He had these buildings demolished and commissioned Giuliano da Sangallo to build the present-day Palazzo Gondi. Work stated on July 29, 1490. Here an inscription recalls: «LEONARDO DA VINCI / lived his auspicious youth / in a house owned by the ARTE DEI MERCATANTI / that was bought and demolished by GIULIANO GONDI / to build this palace / at the completion of which in MDCCCLXXIV / the commune and the owner by common accord / desired to preserve the memory of such a name / on this fine and noble building / to enhance its decorum».

It is interesting to note that Leonardo mentions in the Codex Atlanticus (f. 1024v), among his other friends, Giuliano Gondi, who was engaged in many commercial activities outside of Florence; his sons, in fact, worked in Naples, in Hungary and in Constantinople.

Leonardo's relations with the Medicean dynasty were important and long-lasting. Already his father had had a close relationship with members of the family, establishing a solidarity that would continue up to the time of the Medici's return with Giuliano, Piero and Giovanni (Pope Leo X).

Among the numerous members of the Medici family who exerted an influence on Leonardo and the persons close to him were:

Cosimo the Elder (1389-1464).
Piero di Cosimo (known as Il Gottoso, the Gouty, 1416-1469: to him and his brother Giovanni (1421-1463) was dedicated, in Brunelleschi's Old Sacristy in San Lorenzo, the funerary monument carved by Verrocchio in 1472 with details that recall Leonardo's Annunciation in the Uffizi.
Lorenzo di Piero, known as the Magnificent (1449-1492).
Giuliano di Piero (1453 - assassinated in the conspiracy of 1478): «Painting of a standard with a sprite for Giuliano's joust», one of the works on which Verrocchio and Leonardo collaborated.
Lorenzo di Pierfrancesco, known as Il Popolano (1463-1503), Lord of Piombino: «Grammar book of Lorenzo de’ Medici» in a memorandum in the Codex Arundel, f. 190v.
Piero di Lorenzo (1472 - 1503): «To Fiesole with Piero and Leonardo», wrote the Florentine poet Bernardo Bellincioni to Lucrezia Tornabuoni, the mother of the Magnificent. Giovanni di Lorenzo (Pope Leo X, 1475-1521). Giulio di Giuliano (Pope Clement VII, 1478-1534).
Giuliano di Lorenzo (Duke of Nemours, 1479-1516).
Lorenzo di Piero (Duke of Urbino, 1492-1519).

In his youth, Leonardo remained at the margins of the philosophical circles, but was undoubtedly at the centre of the artistic ones, such as the Garden of Lorenzo.
Around 1482 he went to Milan to bring as a gift to Ludovico il Moro a silver lyre sent him by Lorenzo the Magnificent. For the Medici he drew the cartoon for a tapestry with Adam and Eve, destined to the King of Portugal. At different times he frequented the Villa of Careggi (in the Rifredi-Terzolle area) and the Villa of Poggio a Caiano. At the time of Cesare Borgia he met with Giuliano again, who was in exile. Starting from 1513, after the return of the Medici and the election of Giovanni to the papal throne, Leonardo, although moving to Rome with Giuliano, returned frequently to his native city. In Florence he studied a new Medicean palace opposite Palazzo Medici Riccardi and a rearrangement of the surrounding quarter, with the church of San Giovannino and the façade of San Lorenzo moved to new locations. He also designed the Medicean Stalls.

Leonardo mentions «Pandolfino» in two memorandums in the Codex Arundel and on folio RLW 12675. Francesco Pandolfini, Florentine ambassador to the court of the King of France, wrote to the Signoria reporting that Louis XII wished for Leonardo to remain in Milan in 1507 as his painter and engineer.

Among the Pandolfini family were 28 priors and 12 gonfaloniers in Florence. The family also had the patronage of the Badia Fiorentina, where it ordered the funerary monument to Giannozzo, the work of Rossellino's shop, and the portal of Benedetto da Rovezzano (1495). The residence of the Pandolfini - at the time of Leonardo - stood in the street that bears their name today (between Via Verdi and Via del Proconsolo). Around 1520 the family moved to the palazzo in Via San Gallo built to the design of Raphael by Francesco and Bastiano (known as Aristotele) da Sangallo. Among the most interesting examples of a Late Renaissance palazzo in Florence, it is distinguished by the presence of only two storeys instead of the canonical three.

Leonardo mentions the Pazzi family several times. In a memorandum in the Codex Arundel he writes: «Go to the Pazzi house [...]» and in Madrid Ms. II: «Cornazano de re militari, Guglielmo de’ Pazi has it». Evidently he frequented their home, situated in the piazza that still today bears their name, and was called "courtyard" for the vast garden that stretched from Borgo degli Albizi to Via dell’Oriuolo.

Of course Leonardo followed the vicissitudes of the conspiracy against the Medici in 1478, as shown by the famous drawing of the "Hanged man" in Bayonne, and studied Brunelleschi's architecture in the Pazzi Chapel in Santa Croce.

The palazzo stands in Via della Vigna Nuova, facing the little triangular piazza of the same name, with the Loggia that also bears the name of this important Florentine family intermarried with the Medici and on friendly terms with Leonardo's father.

It was built in the mid-fifteenth century by Bernardo Rossellino to the design of Alberti for Giovanni Rucellai, whose name derives from "oricello", a purple dye extracted from lichens, which was used to dye fabrics and was produced in Via degli Orti Oricellari.

The style of this palazzo inspired the architecture of some of the most important Florentine palaces in the second half of the 15th century, even exerting its influence over the Palazzo Piccolomini designed by Bernardo Rossellino at Pienza. The only hydraulic device designed by Leonardo whose invention is documented is the water meter said to have been sent by him from France to Bernardo Rucellai, as stated in the manuscript of Lorenzo and Benvenuto della Volpaia now in the Marciana Library in Venice.

On March 22, 1508, at the end of what is considered Leonardo's second stay in Florence prior to his second sojourn in Milan, he still lived «in the house of Piero di Braccio Martelli» (previously mentioned by Leonardo around 1503) together with the sculptor Giovan Francesco Rustici, whom he assisted in sculpting three bronze statues to adorn the outside of the Baptistery (the Preaching of St . John). Here he began to compile a part of the Codex Arundel: «Begun in Florence in the home of Piero di Baccio Martelli on the day of March 22, 1508. And this is a collection without order taken from many papers, which I have copied here, hoping then to put them in order in their proper places, according to the matters of which they treat; and I believe that before I come to the end of this endeavour, I will have repeated the same thing several times; so that, Reader, do not criticize me, because the things are many and memory cannot retain them well enough to say: this I will not write, because I have already written it. And if I wished to avoid such an error, I would always have to read everything already written, in every case that I wanted to copy, so as not to repeat it, resulting in long intervals of time between each of the writing sessions».

At present the fourteenth-century Via degli Spadai is called Via Martelli. The residence of Piero di Braccio Martelli was encapsulated in the Scolopi boarding school (up to 1775 a Jesuit monastery), when it was enlarged in 1836. On the façade is a stone tablet commemorating Leonardo's presence here.

Monteoliveto is the hill at the gates of Florence, just outside San Frediano, where in 1472 the church of San Bartolomeo with its monastery was enlarged and remodelled in Renaissance style. In 1867 the Annunciation, formerly attributed to Domenico Ghirlandaio and today attributed by most critics to Leonardo, was taken from here and transported to the Uffizi.

In the church is a Last Supper by Sodoma, a follower of Leonardo.

The Monastery of San Donato a Scopeto with its church was situated just outside the walls of Florence (in the vicinity of the "Gattolina" gate, that is, Porta Romana), toward today's Via Foscolo, close to Bellosguardo and not far from Monteoliveto. The ancient monastery was bought by the Cistercian monks of Badia a Settimo in 1370 and by the Augustinians in 1420. Ser Piero Da Vinci was their notary.

For them Leonardo began, in 1481, the great panel of the Adoration of the Magi, which he left unfinished when he departed for Milan; the commission was then given to his friend Filippino Lippi. Both paintings are in the Uffizi today.

In 1529, the year when Florence was besieged by the army of Charles V, the monastery and church were destroyed and the precious paintings kept there, which included those of Botticelli, were moved elsewhere. The marbles of the portico were instead reutilised in 1575 for the church of San Jacopo Soprarno.

Leonardo frequently refers to San Marco: for its library, for Gherardo "miniator" (who "illuminated" manuscripts also for the King of Hungary Mattia Corvino), for the garden of Lorenzo the Magnificent and for the project for the Medicean quarter datable to 1515.

One of the major centres of Florentine cultural and religious life, this was also the scenario of Savonarola's rise and fall. Of notable importance in relation to Leonardo's Last Supper in Milan is the fresco of the same subject painted by Ghirlandaio in this monastery. Framed by the splendid context of Michelozzo's architecture are the frescoes of Fra Angelico in which, along with the hand of collaborators such as Alessio Baldovinetti and Benozzo Gozzoli, the influence of Masaccio is clearly apparent.

The Baptism of Verrocchio, as the painting now in the Uffizi is usually called, shows the participation of Leonardo in the landscape, in the angel on the left and in other details. It comes from the church of San Michele in Piazza San Salvi, the only church outside the city's walls that was not razed to the ground during the siege of 1529.

The building retains its Romanesque layout, with the sixteenth-century addition of a portico with three front arcades and one side arcade. Noteworthy are a sculpture attributed to Orcagna in the right transept, two bas-reliefs by Benedetto da Rovezzano in the fourteenth-century cloister and the Last Supper by Andrea del Sarto in the refectory. The polyptich of the Blessed Humility by Pietro Lorenzetti has been moved from the church to the Uffizi

With Leonardo, Luca Pacioli also came to Florence in 1500, where he stayed in the Franciscan monastery of Santa Croce.

As reported in the Codex Atlanticus, the Regent of Santa Croce, Master Giovanni, wrote to Leonardo on April 17, 1503 in regard to Saint Ignatius of Antioch and the Virgin Mary. Leonardo sent an answer through one of his collaborators concerning a commission previously discussed with Master Zaccaria, stating that: «between us no money must pass». This episode is still enigmatic, pending the finding of new elements. It refers to theological questions and to a work for which no monetary recompense was contemplated.

This architectural complex contains an incomparable series of masterpieces admired by Leonardo, such as the cycle of frescoes by Giotto and the Crucifix of Cimabue in the refectory, taken by him as model, like Brunelleschi's Pazzi Chapel in the first cloister.

Returning to Florence not later than April 24, 1500, Leonardo took the place of Filippino Lippi in the commission for executing the paintings for the high altar of Santissima Annunziata. For this reason he accepted the hospitality of the monks, going with his assistants to lodge in the monastery.

In 1550 Vasari writes that, «Upon returning to Florence, Leonardo found that the Servite friars had commissioned Filippino to paint the altarpiece for the high altar in the Nunziata; this caused Leonardo to declare that he would gladly have painted a similar work. Upon hearing this Filippino, like the kind and gentle person he was, withdrew, and so that Leonardo might paint it, the friars took him into their household, paying the expenses for him and his whole family. Then Leonardo kept them waiting for a long time without ever beginning anything. During this time, he did a cartoon representing Our Lady and Saint Anne with the figure of Christ, which not only amazed all of the artisans but, once finished and displayed in a room, drew men, women, young and old to see it, as if going to a solemn festival, to gaze upon the marvels of Leonardo, which stupefied the entire populace. For in the face of this Madonna all the simplicity and beauty that can justly be attributed to Christ's mother can be seen, since Leonardo wished to show the modesty and humility of a virgin delighted to gaze upon the beauty of her child, who holds Him tenderly in her lap, while with a modest downward glance she notices Saint John as a little boy who is playing with a lamb, not without a smile from Saint Anne, overjoyed to see her earthly progeny become divine.»

Fra Pietro da Novellara, in a letter to Isabella d’Este dated April 3, 1501, confirmed that Leonardo was working on the cartoon for the Saint Anne; the location of the latter, which is not the one now in the National Gallery of London, is still unknown.

In the offices of the Military Geographic Institute there have recently been found, adjacent to parts of the building still owned by the monastery, the rooms where Leonardo would have been able to lodge for a long time and probably to work on the "marvels" of the cartoon. Although having been remodelled more than once, these rooms can be attributed to the great architect Michelozzo, who belonged to Brunelleschi's circle. The suggestion that some frescoes still existing in these rooms should be attributed to Leonardo is instead groundless.

The church of Santissima Annunziata was remodelled around 1440 by Michelozzo, but its rotunda was designed by Leon Battista Alberti. The portico is the work of Antonio da Sangallo, while in the Chiostrino dei Voti are found, in addition to a Nativity by Alessio Baldovinetti with a landscape that undoubtedly caught the attention of Leonardo, frescoes by the leading figures in Mannerism who came after Leonardo, such as Pontormo, Rosso Fiorentino and Andrea del Sarto.

When the Signoria commissioned Leonardo to paint the Battle of Anghiari, on October 24, 1503, he was given the keys to the Pope's Room in Santa Maria Novella, where he was to make the preparatory cartoon for the great wall painting that was to adorn the east wall of the Great Hall in Palazzo Vecchio, over a space 18.8 wide and 8 meters high.

In February 1504, payments are recorded for «building the scaffolding for said cartoon» and for many other preliminary jobs and expenses.

The cartoon was then brought to Palazzo Vecchio, where it was used for transferring the composition of the Battle of Anghiari onto the wall. In the great hall, facing Michelangelo's cartoon for the Battle of Cascina, it constituted that marvel hailed by Benvenuto Cellini as the "School of the world" for the influence it exerted on the artists who saw it. Although no one yet knows where it is, it is hard to believe that it has been lost.

Santa Maria Novella undoubtedly represented for Leonardo a fundamental lesson in the various artistic expressions of the Early Renaissance, with Alberti's façade (commissioned by the Rucellai family), the Gondi chapel (designed by Sangallo, with a Crucifix by Brunelleschi), the Tornabuoni chapel (with Ghirlandaio's frescoes), Giotto's Crucifix in the sacristy, Masaccio's Trinity (fundamental also as regards the concept of perspective), Brunelleschi's pulpit, the Rucellai chapel (with Cimabue's Madonna Enthroned, later moved to the Uffizi), the Green Cloister with the frescoes of Paolo Uccello (including the extraordinary Deluge), and the Spanish Chapel (frescoed by Andrea di Bonaiuto).