Leicher came to Vienna from the Silesian town of Wagstadt, with the support of Piarist fathers. Already in 1751 he was a pupil at the Viennese Academy. In 1754 he won second prize in the academic competition, which made him a supported member of the Academy. He worked for a long time with Franz Anton Maulbertsch,
with whom be was in friendly relations all his life. However, as he was not engaged in fresco painting, he employed the artistic message of Maulbertsch in panel painting. Primarily he painted altarpieces,
in many cases for the churches where the frescoes were executed by Maulbertsch.
He worked permanently for his patrons, the Piarists in Austria, Bohemia, Moravia, Silesia and Hungary. In several cases his works were attributed by posterity to Maulbertsch,
and the bulk of his altarpieces and panel paintings only recently were identified as his productions. It is almost sure that several of his works still lie hidden in remote churches and collections. Sometimes a genre painting
surprisingly reveals itself as his work (Budapest, Museum of Fine Arts), and sometimes an anonymous 18th century sketch or drawing bears traces of his hand.
His compositions, loose modelling, effective lighting and characteristic types undoubtedly betray the influences and ideas of Maulbertsch,
Leicher s approach, however, is softer and weaker, without the expressive power, dramatic vitality or pictorial virtuosity of his master.