From 1953 to 1961, Ørberg worked in the Naturmetodens Sproginstitut[b], an institute where languages are taught according to the "natural method" of learning.

[a][2] In his retirement, Ørberg directed the Domus Latina[d] publishing house and gave lectures in Europe and the United States on the natural method.

Ørberg's LINGVA LATINA PER SE ILLVSTRATA[a] is based on the natural method,[3] or contextual induction.

[4] In this method, the student, who needs no previous knowledge of Latin, begins with simple sentences, such as Rōma in Italiā est ("Rome is in Italy").

The course consists of two parts: FAMILIA ROMANA[e] and ROMA AETERNA[f], along with a series of classic texts like Julius Caesar's Commentāriī dē Bellō Gallicō.