Wilhelm Tempel was born in Germany in a poor family. At age 16, he moved to Meissen to learn lithography. Four years later, he was in Copenhagen where he perfected his technique for three years, then he stayed in Norway. Attracted by Italy, he settled in Venice in 1850 as a lithographer and developed an active interest in astronomy. He corresponded with Benjamin Valz (1787-1867), head of the Observatory of Marseilles, and aimed at becoming a professional astronomer. Urbain Le Verrier (1811-1877) refused him in Paris, but Valz hosted him in Marseilles in 1860, albeit without a salary (he continued to make a living as a lithographer). He remained at the observatory for 10 years, which was in the meantime moved to a new location and well equipped. His relationship with Le Verrier, director of the Paris Observatory, of which the Marseille facility was then a subsidiary, was stormy. After Le Verrier’s dismissal in 1870, he looked for a permanent position in Paris, but it was too late: war broke out and Tempel, who could not obtain French nationality, had to leave France. Giovanni Schiaparelli (1835-1910) hired him as an assistant in the observatory of Brera, near Milan, which finally enabled him to devote himself entirely to astronomy. Then in 1874, he became deputy director of the Observatory of Arcetri, near Florence, which was not finished but began to be equipped with good telescopes. Finally recognized by his peers, he remained subject to persecution by the Italian authorities until his death in 1886. These permanent vicissitudes did not prevent Tempel from discovering many comets: one during his stay in Venice, eight in Marseilles, five in Brera, then another one in Arcetri. He also discovered five asteroids and 186 nebulae.