Complex sentence: The "Garde" was founded through the amalgamation of various militia groups created by the middle classes during the anarchy following the revolution and acted as a quasi-military "gendarmarie", with the primary role of maintaining social order within Belgium until its disestablishment in 1920.
Split into simpler sentences: The "Garde" was founded through the amalgamation of various militia groups created by the middle classes during the anarchy following the revolution. As a formation, it acted as a quasi-military "gendarmarie", with the primary role of maintaining social order within Belgium until its disestablishment in 1920.