Franciscus Junius (29 January 1591 – 1677), also known as François du Jon, was a pioneer of Germanic philology. As a collector of ancient manuscripts, he published the first modern editions of a number of important texts. In addition, he wrote the first comprehensive overview of ancient writings on the visual arts, which became a cornerstone of classical art theories throughout Europe.
Junius was born in Heidelberg. He was brought up at Leiden, Netherlands as his father, also called Franciscus Junius, was appointed professor of Hebrew at Leiden University in 1592. In 1602 his parents died, and Junius went to live with his future brother-in-law, the humanist scholar Gerhard Johann Vossius in Dordrecht. He studied theology at Leiden and Middelburg.
In 1617, he became a pastor at Hillegersberg, near Rotterdam. He resigned this position the following year, after he refused to take sides in a theological conflict in the Dutch Reformed Church, centering on faith out of free will as advocated by Jacobus Arminius or faith out of predestination, as defended by Junius' uncle Franciscus Gomarus. After his resignation, Junius elected to travel instead: he visited first France, and then moved to England, where in 1620 he was employed by Thomas Howard, earl of Arundel, as a tutor to his son, and later as librarian. It was for Arundel, an avid collector of Greek and Roman art objects, that Junius wrote his De pictura veterum, a theoretical discussion of classical art and one of the cornerstones of the Neoclassical movement. Published in 1637 in Latin, it was followed by his own translations into English (1638) and Dutch (1641); the latter edition was written with a readership of artists in mind.