Nils Arne Eggen (born September 17, 1941 in Orkdal, Sør-Trøndelag, Norway) is a personality that really stands out in Norwegian soccer history. He is best known as the manager for Rosenborg B.K in the period 1988 - 1997 and 1999 - 2002. This period is often referred to as "The Golden Age" for the club.
Nils Arne resigned as manager for Rosenborg in 2002, and Åge Hareide took over as manager. Two of Nils Arne's last achievement was winning the Norwegian Premier Division (11th time in a row), and qualifying for the European Champions League (8th time in a row).
He began his active football career when he was 15 years old as a defender at Orkdal's senior team. Later on he moved to Trondheim to study, and felt it naturally to join Rosenborg. Nils Arne enjoyed winning the Norwegian Football Cup with them in 1960.
In 1963 he moved to Oslo where he soon joined Vålerenga. They won the Norwegian Premier Division in 1965, before he moved back to Trondheim where he played an important role for Rosenborg when they won the Premier Division twice before he decided to quit his football career.
He was soon appointed as Rosenborg's coach, together with Tor Røste Fossen, and in his first season (1971) they won "the double" - first time ever in the club's history. During the seventies he also managed both the national youth team and the national senior team.