- 1851 the first efterskole founded at Ryslinge, Fyn (Funen).
- 1874 several efterskoles founded along the Danish-German border facilitating schooling for Danish students from German occupied land. Efterskoles become boarding schools, so that students need not cross the border.
- 1879 Galtrup Efterskole established. This school is today the oldest existing efterskole.
- 1930 the first act concerning efterskoles passed in the Danish Parliament. Major changes in this legislation in 1942, 1954, 1967, 1970, 1992, 1994, 1996, and 2000.
- 1960-67 problems recruiting students in the efterskole lead to debate on whether to change the efterskole from being like a Folkehøjskole for the young (non formal education), to moving towards the Folkeskole (municipal school) with fixed curriculum and exams.
- 1967 the efterskole is permitted to prepare students to pass some of the public final examinations. From this point the efterskole ceases to be closely linked to the Folkehøjskole tradition – at least in the aspect of nonformal education. On the other hand, the efterskole still offers the special educational environment linked to residential education, which is also an important aspect of the Folkehøjskole tradition and, in its educational practice, it has definitely not left the path of ‘enlightenment for life’. One could claim that from this point the efterskole tries to balance between different educational ideas and requirements.
- 1975 the efterskole is permitted to offer all the same final examinations as the Folkeskole.
- 1975-00 each year several new efterskoles are founded and the total student body doubles, as does the number of schools in this period.
- 1994 municipal grants are made compulsory, which improves and equalises the economical conditions for students (and their parents) – independent of their local council. In the following years the result is evident: a broader section of the population can now afford to choose the efterskole – and so they do. The 1994 act also transfers significantly more assessments, decisions, and responsibility from central level (Ministry of Education) to the local school board. Essential topics like the educational plan and the approval of a new headmaster lie from this point entirely in the hands of the school board.
- 1996 the Danish Parliament in a significant law reform tightens up and emphasises the conditions for receiving state funding: an efterskole must (prove itself to) be free and independent. Under no circumstances may the school from a legal point of view have strong organisational and financial links to – or be dependent on – other schools or movements. The decisions, activities, arrangements and investments may only take place for the benefit of the individual school and the students attending it. Each efterskole must be truly free and independent, and "master in its own house". This puts even more responsibility on the school board. As a consequence of the 1996 law reform, the schools originating in the extensive, controversial and internationally wellknown Tvind School Cooperation lost their state approval and their state funding.
- the latest efterskole act introduces a new rule that each efterskole must define and describe its own (and specific) basic values. A critical self-evaluation must be made at the end of each school year.