Johan Julius Exner, (30 November 1825 – 15 November 1910), Danish genre painter, was born in Copenhagen to Johann Gottlieb Exner, a Czech musician from Bohemia, who came to Denmark during the Napoleonic period, and his wife Karen Jørgensdatter. Exner originally intended on becoming a history painter, but quickly found his niche, however, in genre painting, the most popular and lucrative painting style of his era. His genre paintings figured prominently in Denmark's National Romantic period, an artistic period directly after the Golden Age of Danish Painting, when artistic focus was turned inwards to uniquely Danish themes.
The younger Exner was interested in drawing and painting from an early age and was put in private training after his confirmation. He began to study at the Royal Danish Academy of Art (Det Kongelige Danske Kunstakademi) April 1839, where he intended on becoming a history painter. He caught the attention of Professor J. L. Lund, from whom he learned history painting. He studied later on with Christoffer Wilhelm Eckersberg, closely linked to the Golden Age of Danish Painting and commonly referred to as the Father of Danish Painting.
In 1844 he exhibited his first painting "Fra Kunstakademiets figursal" ("From the Art Academy's Plaster Cast Collection") painted in 1843; the painting depicts a student sketching a plaster cast of a statue in the Academy's plaster cast collection, another student in the background moves between the figures.
He won the Academy's little silver medallion in 1843, and the large silver medallion in 1845. In these early years he exhibited several history paintings as well a number of portraits. One of these portraits, a portrait of his sister, won him the Academy's Neuhausens prize (Neuhausens præmie) in 1847.