A handful of Cossacks patrolled a patch of central Moscow as part of a resurgence encouraged by President Vladimir Putin.
By tradition, Cossacks protected Russia's borderlands, but the descendants of the Tsarist warrior caste carried out a trial run in the Russian capital today.
The men in high lambswool hats and epaulettes paced a slushy square around a major railway station, looking for illegal trade and other infractions.
While a few venders in a chilly underpass left when Cossacks approached, the patrol - unarmed and outnumbered by journalists - was uneventful for a group with a reputation as whip-wielding horseback warriors protecting frontiers from foreign threats.
But it was a sign of a Cossack revival that plays into Mr Putin's calls for patriotism and his praise of Russian traditions - and which critics say aggravates the ethnic tension the president has struggled to keep under control.
Moscow's central district administration and the Cossack affairs department released a statement saying the patrol was the "personal initiative" of a Cossack leader.
It also said Cossack patrols could begin on a official basis early next year.
The Cossacks cannot make arrests or check documents. They receive free public transport but no pay, city officials said.
Claiming descent from nomads and fugitives from serfdom who served tsars with their swords and lived in relative freedom on Russia's edges, Cossacks are symbols of Russian patriotism.
Their past is also coloured by anti-Jewish pogroms in the tsarist era, and their nationalism is a volatile additive to tension between ethnic Russians and minorities in cities such as Moscow, where many migrants are Muslims from the North Caucasus and ex-Soviet republics in Central Asia.
Cossacks faced systematic killings and deportation at the hands of the communists following the Russian revolution, but have enjoyed a resurgence since the 1991 Soviet collapse.