A CHRONOLOGY OF GALILEO

1543   Nicolaus Copernicus (1473–1543) publishes On the Revolutions of the Heavenly Spheres and Andreas Vesalius (1514–64), On the Fabric of the Human Body.

1545   Council of Trent convenes and will be in session off and on for eighteen years until 1563.

1551   The Roman College (now the Pontifical Gregorian University) founded by the Jesuits in Rome.

1559   First worldwide Index of Prohibited Books promulgated by the Roman Catholic Church.

1564   Galileo is born in Pisa, on 15 or 16 February; Michelangelo Buonarroti dies in Florence on 18 February.

1581   Galileo enrols at University of Pisa.

1585   He abandons studies at Pisa without taking a university degree. He considers becoming a painter but decides to study mathematics.

1587   Galileo goes to Rome to discuss his essay on the centre of gravity of solids with Christopher Clavius, a Jesuit professor at the Roman College and the most famous astronomer of his day. During this period he also writes on the balance and on Archimedes.

1589   Appointed professor of mathematics at the University of Pisa; develops a rudimentary thermometer; begins to study falling bodies. His lecture notes indicate that he read the works of Aristotle and those of Christopher Clavius.

1591   Around this time, Galileo drafts a work, On Motion, in which he is critical of Aristotelian philosophy. Galileo’s father, Vincenzio Galilei, dies.

1592   Galileo becomes professor of mathematics at the University of Padua, where he will spend eighteen years.

1593   He writes a Treatise on Fortifications and Architecture for young noblemen to whom he gives private lessons.

1594   Drafts a Treatise on Mechanics that he will revise and enlarge over the next few years.

1597   Writes a Treatise on the Sphere for his students.

1600   Giordano Bruno is burnt at the stake in Rome. Galileo’s first daughter, Virginia, is born in Padua.

1601   Birth of his second daughter, Livia.

1603   Prince Federico Cesi founds the Lincean Academy in Rome.

1604   Galileo gives three public lectures on a new star that appeared in the heavens.

1605   The teenage Prince Cosimo de’ Medici takes instruction from Galileo in the summer in Tuscany.

1606   Galileo publishes sixty copies of the Operations of the Geometric and Military Compass, an instrument that he manufactured and sold. His son, Vincenzio, is born in Padua.

1607   Baldessar Capra publishes a pirated Latin edition of Galileo’s Operations of the Geometric and Military Compass. Galileo sues him and publishes an account of the incident.

1609   The Grand Duke Ferdinando I dies in Florence; Cosimo II succeeds him. Galileo devises a new telescope, observes and measures mountains on the Moon.

1610   He discovers four satellites around Jupiter and publishes A Sidereal Message. He is appointed chief mathematician and philosopher to the Grand Duke of Tuscany and leaves Padua for Florence.

1611   Galileo visits Rome and is made a member of the Lincean Academy.

1612   He publishes a book on floating bodies.

1613   Prince Cesi publishes Galileo’s Letters on the Sunspots in Rome. His daughters, Virginia and Livia, enter the Convent of San Matteo in Arcetri outside Florence.

1614   Galileo writes a Letter to Benedetto Castelli in which he argues that the Copernican theory is not at variance with Catholic doctrine.

1615   Galileo expands his Letter to Benedetto Castelli into the Letter to the Grand Duchess Christina that is widely circulated in manuscript but will only be published in

1636   in Holland. He writes his Observations on the Copernican Theory and leaves for Rome where he arrives in December and will stay until June 1616.

1616   Galileo writes his Discourse on the Tides. On 26 February Galileo is given a formal warning forbidding him from holding, teaching, or defending Copernicanism. On 5 March Copernicus’ On the Revolutions of the Heavenly Spheres is placed on the Index of Prohibited Books.

1618   Three comets appear in rapid succession, generating interest and debate. Galileo goes on a pilgrimage to Loreto.

1619   Galileo publishes anonymously a Discourse on the Comets criticizing the interpretation given by the Jesuit professor Orazio Grassi who replies in a work entitled The Philosophical and Astronomical Balance.

1623   Maffeo Barberini becomes Pope Urban VIII. Galileo dedicates The Assayer to him.

1624   Galileo travels to Rome and sees the Pope six times in as many weeks.

1629   Bubonic plague enters northern Italy from Germany.

1630   Galileo returns to Rome to obtain a printing licence for his Dialogue Concerning the Two Chief World Systems. Prince Cesi dies. Bubonic plague strikes Florence, where the deaths will amount to ten thousand.

1631   Galileo’s brother, Michelangelo, dies of plague in Germany.

1632   The Dialogue Concerning the Two Chief World Systems—Ptolemaic and Copernican is published in Florence.

1633   Galileo stands trial in Rome. His Dialogue is prohibited and he is sentenced to house arrest.

1634   His daughter Virginia (in religion Suor Maria Celeste) Galilei dies in Arcetri.

1637   Galileo loses his eyesight.

1638   Louis Elsevier publishes Galileo’s Two New Sciences in Leiden, Holland.

1641   Vincenzio Galilei draws his father’s design for a pendulum clock.

1642   Galileo dies in Arcetri on 8 January.

1644   Pope Urban VIII dies.