Politically opposed groups arose in the "Second National Assembly" - as it was called. The more progressive elements, under Konstantinos Kanaris and Theodoros Grivas, were named "Mountain men" (Greek: Ορεινοί) while the more conservative forces, under the leadership of Dimitrios Voulgaris, were named "Plains Men" (Greek: Πεδεινοί) for the simple reason that the progressives occupied the higher seats in the Assembly's chamber while the conservatives occupied the lower ones.
On April 29, 1863, Benizelos Rouphos formed a government that excluded "Plains men". Dimitrios Voulgaris and his supporters resented their defeat and took to the streets. On June 18, clashes started that lasted three days. More than 200 civilians and soldiers were killed before the rioting stopped with the intervention of the Ambassadors of Britain, France and Russia.
Slowly, the distinction between "Mountain men" and "Plains men" was abandoned and the latter group ceased to exist after 1875. For their part, the "Mountain men" split into two groups, shaping the political situation of Greece until 1909.