The first time I heard this song was by the Mediaeval Baebes on their "Mirabilis" album and I was instantly struck with it's sad beauty. This song was written in the 18th century by author Carl Michael Bellman as part of the "Epistles of Fredman", a collection of poems and songs that chronicle fictional characters and events that took place around Stockholm during that era. Most of these fictional characters were based on people Bellman knew in real life and center around the character Jean Fredman, an alcoholic watchmaker.
Born in The Netherlands in 1937, Cornelis Vreeswijk moved to Sweden with his parents in 1949 at the age of 12. He was trained as a social worker and had hoped to become a journalist, but became a musician instead. He led a very colorful life, full of controversy - drink, debt, and questionable characters. He died in 1987 of liver cancer at the age 50.
Märk Hur Vår Skugga by Cornelis Vreeswijk from the album "Gömda Guldkorn"
Wikipedia biography of Cornelis Vreeswijk
Dutch website for Cornelis Vreeswijk