What Walter Pater wrote of the Renaissance—“in many things great rather by what it designed or aspired to than by what it actually achieved”—could be a summation of Leonardo’s own lifetime of effort in science. He labored to bring mankind from the morass of medieval superstitions onto the firm ground of natural facts. With an insatiable curiosity Leonardo attempted the impossible task of encompassing all knowledge. Thus he established his right to immortality—for it was an attempt that shone like a beacon in a world dark with ignorance. _Significant Dates in Leonardo’s Life_ 1452 April 15. Birth of Leonardo. 1467 Commences apprenticeship with Verrochio in Florence. 1478 Commissioned for altarpiece in the Palace of the Signoria. 1481 Commissioned to paint an altarpiece for Convent of San Donato. 1482-83(?) Leonardo leaves Florence for the court of Ludovico Sforza in Milan. 1483 Begins equestrian monument of Francesco Sforza for Ludovico. 1484-86 Plague in Milan. 1490 April 23. Recommences equestrian monument and starts book on light and shade. 1496 Meets with Fra Luca Pacioli, professor of mathematics. 1498 _The Last Supper_ completed. 1499 Apr. Land awarded to Leonardo near Porta Vercellina. Oct. French occupy Milan. Dec. Leonardo leaves Milan with Pacioli. 1500 Leonardo arrives in Mantua. Travels to Venice and returns to Florence. 1502 In the service of Cesare Borgia. 1503 Returns to Florence, commences work on a canal to sea. 1504 Begins the painting of battle of Anghiari. Father dies. Attempt at flight (?). 1506 May. Leaves Florence for Milan at summons of Charles d’Amboise, French military governor. 1507 Sept. Goes to Florence to settle father’s will. 1508 July. Returns to Milan. 1511 Works with Marc Antonio della Torre on anatomical research. 1512 French lose Milan. 1513 Leonardo leaves Milan for Rome. Serves Giuliano de’ Medici, brother of Pope Leo X. 1516 Leonardo leaves Rome for France to serve King Francis I. 1519 May 2. Death of Leonardo. _Index_