Question: What is the piece by Lorenzo Ghiberti which Michelangelo called "the Gates of Paradise" also known as?

Context articles: History of Italian Renaissance domes
Andrea di Giusto
Lorenzo de' Medici
St. John the Baptist (Ghiberti)
Bernardo Cennini
Lorenzo Ghiberti
Florence Baptistery
San Girolamo, Volterra
A Season of Giants
Giovanni dal Ponte

After years of considering options, Filippo Brunelleschi and Lorenzo Ghiberti were made joint leaders of the project to build the dome for Florence Cathedral in 1420.
 Brunelleschi's plan to use suspended scaffolding for the workers won out over alternatives such as building a provisional stone support column in the center of the crossing or filling the space with earth.
 The octagonal brick domical vault was built between 1420 and 1436, with Ghiberti resigning in 1433.
 The lantern surmounting the dome, also designed by Brunelleschi, was not begun until 1446, after his death.
 It was completed in 1467.
 He had also planned for a two-story external gallery and cornice to be built at the top of the drum where a strip of unclad masonry can be seen today.
 Although a portion of it was constructed on the southeast side beginning in 1508, work stopped after the visual effect was criticized by Michelangelo.
Andrea di Giusto (c. 1400- 2 September 1450, Florence), rarely also known as Andrea Manzini or Andrea di Giusto Manzini was a Florentine painter of the late Gothic to early Renaissance style in Florence and its surrounding countryside.
 Andrea was heavily influenced by masters Lorenzo Monaco, Bicci di Lorenzo, Masaccio, and Fra Angelico, and tended to mix and match the motifs and techniques of these artists in his own work.
 Andrea was an eclectic painter and is considered a minor master of Florentine early Renaissance art.
 Andrea trained under Bicci di Lorenzo as a "garzone".
 He painted his most significant works, three altarpieces, in the Florentine contado, or countryside; these altarpieces were created for Sant’Andrea a Ripalta in Figline, Santa Margarita in Cortona, and the Badia degli Olivetani di San Bartolomeo alle Sacce near Prato.
 Aside from his major altarpieces, Andrea painted several Frescoes over the course of his career.
 He, along with other minor masters, are also known to have provided several different types of art, including triptychs and frescoes, for Romanesque pievi, or rural churches with baptistries.
 Moreover, he was well-known for several types of smaller craft objects, such as small tabernacles.
 He is said to have worked between 1420 and 1424 under Bicci di Lorenzo on paintings for Santa Maria Nuova.
 In 1436, he is said to have worked with Masaccio in painting the "Life of San Giuliano" for the Polyptych of Pisa, including the painting of the "Madonna and Child".
 He also appears to have collaborated in 1445 with Paolo Uccello in the Capella dell'Assunta in the Prato Cathedral.
 In 1428, he is listed as a member of the "Arte dei Medici e Speziali" guild in Florence as "Andrea di Giusto di Giovanni Bugli".
 His son, Giusto d'Andrea, was also a painter and worked with Neri di Bicci and Benozzo Gozzoli.
 Andrea died in Florence in 1450.
Lorenzo de' Medici (] , 1 January 1449 – 8 April 1492) was an Italian statesman and "de facto" ruler of the Florentine Republic, who was the most powerful and enthusiastic patron of the Renaissance.
 Also known as Lorenzo the Magnificent ("Lorenzo il Magnifico" ] ) by contemporary Florentines, he was a magnate, diplomat, politician and patron of scholars, artists and poets.
 He is well known for his contribution to the art world by sponsoring artists such as Botticelli and Michelangelo.
 His life coincided with the mature phase of Italian Renaissance and his death coincided with the end of the Golden Age of Florence.
 The fragile peace that he helped maintain among the various Italian states collapsed with his death.
 He is buried in the Medici Chapel in Florence.
St. John the Baptist (1412–1416) is a bronze statue by Lorenzo Ghiberti located in one of the 14 niches of the Orsanmichele in Florence, Italy.
 The statue of the Saint was commissioned by the cloth merchant's guild, the "Arte di Calimala".
 The artist's use of the unnaturalistic but elegant curves in the hair and drapery of the saint show the influence of the International Gothic style prevalent in Italy at the time the work was created.
 The work was successfully cast in a single piece, making it the first bronze statue of its size to be cast in a single piece for at least several hundred years in Italy.
Bernardo Cennini (] ; 1414/5 – c. 1498) was an Italian goldsmith, sculptor and early printer of Florence.
 As a sculptor he was among the assistants to Lorenzo Ghiberti in the long project producing the second pair of doors—the "Doors of Paradise"—for the Battistero di San Giovanni.
 He produced the first book printed at Florence.
 The painter and author of a famous book on the crafts, Cennino D'Andrea Cennini, was a member of the same Florentine family.
Lorenzo Ghiberti (] ; 1378 – 1 December 1455), born Lorenzo di Bartolo, was a Florentine Italian artist of the Early Renaissance best known as the creator of the bronze doors of the Florence Baptistery, called by Michelangelo the "Gates of Paradise".
 Trained as a goldsmith and sculptor, he established an important workshop for sculpture in metal.
 His book of "Commentari" contains important writing on art, as well as what may be the earliest surviving autobiography by any artist.
The Florence Baptistery (Italian: "Battistero di San Giovanni" ), also known as the Baptistery of Saint John, is a religious building in Florence, Italy, and has the status of a minor basilica.
 The octagonal baptistery stands in both the Piazza del Duomo and the Piazza San Giovanni, across from Florence Cathedral and the Campanile di Giotto.
San Girolamo is an Renaissance style church just outside the old walled city of Volterra, Italy.
 The church and attached Franciscan convent, a complex also known as of "San Girolamo al Velloso", were designed by Michelozzo and construction was completed by about 1445.
 Some have questioned the attribution and even suggested that it was designed another famous Florentine architect, Lorenzo Ghiberti.
A Season of Giants (Italian: "La primavera di Michelangelo" , also known as "Michelangelo: The Last Giant") is a 1990 American-Italian biographical drama television film directed by Jerry London.
 Based on the Vincenzo Labella's book "Una stagione di giganti", it depicts real life events of Michelangelo, his youth, his approach with art, his friendship with Leonardo and Raphael and his involvement in great political and religious events.
Giovanni dal Ponte (1385 – ca. 1438, Florence) was a Florentine minor master painter of the late-Gothic period, known as one of the greatest minor masters contemporary to Masaccio.
 He is known by Giorgio Vasari as dal Ponte, a name derived from the location of his studio at the Piazza di Santo Stefano a Ponte.
 Many other documents cite his name as Giovanni di Marco.
 After joining the Arte dei Medici e degli Speziali in 1410 and the Compagnia di S Luca in 1413, dal Ponte opened his studio in the late 1420s and hired Florentine painter Smeraldo di Giovanni as his assistant.
 Smeraldo was hired after dal Ponte was imprisoned in 1424 due to failure to repay his debts, with the intention that Smeraldo would manage the logistical aspects of the workshop in addition to his artwork.
 Dal Ponte used his craftsmanship to create not only Panel paintings, but also frescoes and decorations for small objects.
 Dal Ponte's work is considered to be of the Late Gothic style, though he assimilated the stylistic preferences of his contemporaries; Lorenzo Monaco, Masaccio, and Lorenzo Ghiberti served as his primary influences.