The Reign of Peter I was marked by far-reaching reforms enforced under the difficult conditions of war with Sweden. Aside from moving the capital from Moscow to St Petersburg, Peter's most famous decree was probably that ordering all men (excluding clergy and peasants, provided the latter stayed in the countryside) to shave off their beards. As with the proverbial cutting off of braided hair (alte Zöpfe) in the course of the Prussian military reforms of 1807–1814, an enforced change of hairstyle is taken to represent changes in other areas – in the Russian case, of the administration, the military and the Church.
Caricature on the Reform of Peter the Great: A Russian "Old Believer" is Shorn of his Beard, artist unknown, woodcut for a pamphlet, late 17th century; source: Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Raskolnik.jpg?uselang=de, public domain.