Billian originally wanted to become an opera singer but due to the deterioration of his voice during his nine years in military service he had to abandon this plan.
After World War II, he settled in West Germany and started to work as an actor at theatres in Hamburg and Wolfenbüttel.
In the late 1960s and early 1970s, he directed softcore sex comedies, like Pudelnackt in Oberbayern (1969) (a Bavarian sex comedy pioneer), Die Jungfrauen von Bumshausen (Run, Virgin, Run) (1970), and Das Mädchen mit der heißen Masche (Loves of a French Pussycat) (1972) (starring Sybil Danning).
During this period, Billian continued to shoot loops, a number of which attracted particular attention such as Massagesalon Elvira that featured Anne Magle, the Danish porn sensation of the '70s.
Teil was conceived by Billian as the first part of a Josefine Mutzenbacher series but when the producer Gunter Otto of Herzog refused to finance a second part, Billian took the money from the production company Starlight and directed Die Beichte der Josefine Mutzenbacher (Josephine) in 1979.