His father, Martin Jänneg (or Jänickh, ?-1709) was a minor artist, originally from
Croatia. His mother, Anna, was from
Lugano. His brother, Matthias (born 1707) also became a painter. After completing his secondary education in Graz, he took art lessons from a little known still-life painter named Matthias Vangus (fl. 1710s-20s). He moved to Vienna in 1726 and became a student of the
court painter,
Jacob van Schuppen, who had just become Director of the "Hofakademie der Maler, Bildhauer und Baukunst" (now the
Academy of Fine Arts). A short time later, he continued his studies in
Frankfurt with the Hungarian-born painter, . In 1736, he married Anna Maria Canton, daughter of the painter Franz Canton (1678–1733). He returned to Vienna around 1740. Soon after, his paintings began to rely more heavily on Dutch and French models; losing their previous originality. Later, He took over management of a genre painting class at the academy and served as Rector from 1752 to 1754, when he resigned, following his wife's death. Many of his works are in private collections, although they may also be seen at the
Universalmuseum Joanneum, the
Belvedere, the
Brukenthal National Museum and the collections of the
National Gallery in Prague. A street in the
Hietzing district of Vienna is named after him. ==Selected works==