Short answers, pulled from the story.
Johann Nepomuk della Croce was an Austrian painter born on the 7th of August 1736 in Pressano, Tyrol, who worked in a late-Baroque style across Germany and Trentino. He was known in Italy as Giovanni Nepomuceno della Croce. He died on the 4th of March 1819.
Della Croce is estimated to have painted around five thousand portraits and two hundred historical pictures. He also produced many altar-pieces found in churches throughout Bavaria.
After studying under Lorenzoni and travelling through Italy, Germany, Hungary, and France, della Croce settled at Burghausen in Bavaria. He was active in both Germany and Trentino throughout his career.
A portrait of the Mozart family is traditionally attributed to della Croce. The work is one of the most recognized depictions of the Mozart family and has linked della Croce's name to the history of classical music.
Della Croce studied under Lorenzoni, described as an Italian artist. After his training he travelled extensively before establishing his career in Bavaria.
His son Clemente, also known as Clemens della Croce, was also a painter. Clemente was born in 1783 and died in 1823.