They defended czars and terrorized Jews with pogroms. Their horsemanship, bravery, and brutality were legendary.
Then they suffered decades of disrepute under the Communists.
Now they're thundering back.
The western Russian city of St. Petersburg is planning to enlist dozens of Cossack volunteers to help patrol parks in the autumn.
The revival of Cossacks in St. Petersburg forms part of a national trend to restore their name.
In the Far East, for example, a parallel plan is under way to deploy Cossacks on patrols along the border with China.
But the thought of these men dressed in traditional black and red garb riding through the streets on horseback has raised some discomfort among residents, who associate Cossacks with xenophobic attacks against Jews in the late 19th and early 20th centuries.
"They were brave, strong, and patriotic. But I don't know if they are popular," says Denis Chikhantsov, a young cadet who served in the guard of honor during last month's burial of the remains of Russian Czar Nicholas II.
Mr. Chikhantsov expresses admiration for the Cossacks' courage but questions whether they are the most suitable choice to guard the public.
Even more vociferous skepticism is expressed by Viktor Minakov, a Communist legislator who serves on the security committee in the Duma, Russia's lower house of parliament.
"Before the [1917 Bolshevik] Revolution, Cossacks were needed to provide quick action," he says.
"Now, telephones have been invented for that purpose. So they are not necessary anymore."
With law and enforcement not all it should be in this crime-struck nation, however, the call to arms and horse is not something to be feared, officials say. The Cossacks have security acumen that can now be harnessed in the name of peace.
"We have to destroy this myth that they are bad," says Gen. Viktor Vlasov, St. Petersburg's police chief. "Cossacks have a long history of defending the country. Today, they are restoring their own society all over Russia. It is important for them to feel they are contributing to life in the city."
In St. Petersburg, Cossack volunteers would initially join patrols with ordinary policemen. But they won't have powers of arrest. Though they won't wear their traditional sabers, they may carry guns. If successful, the number deployed could grow to 200.
"We'll see how the public receives them," General Vlasov says.
He expects success, judging from past experience. Since 1993, the Cossack organization Grom, or "Thunder," has patrolled railroads by foot, to no ill effect.
Arkady Kramarev, a former police chief and the local Cossack ataman, or traditional leader, says the Cossack volunteers have skills that could make St. Petersburg a better place.
"Cossacks have centuries of experience of state service which formed a certain mentality. They were loyal to their word," says Mr. Kramarev, who also chairs the city legislature's law-and-order commission. "They can lend a special service to the country now, with this sort of anarchy going on."
He adds, with a slightly nostalgic smile: "It will be just like in old times. Cossacks will have a weapon and be on patrol."
The general reassertion of culture, also evident by the plan to use Cossacks on the Russian-Chinese border, is welcomed by the Cossack community. Like other minority groups, it suffered massacres and deportations under Communist rule. All Cossack institutions were abolished following the 1917 revolution, partly because those Cossacks in southern Russian fought against the Bolsheviks. However, some units were revived to fight in World War II.
Such bad treatment prompted a longing for the preferential treatment under the czars, who used the Cossacks to defend Russia's borders and enlarge Russia's territory to the east in the 17th century. In the 16th century, Polish kings even organized Cossacks into military colonies to protect Poland's borders.
The Cossacks - scholars believe the word comes from the Turkic word kazak, meaning free man or horseman - prided themselves on their independence. They had their own self-governing communities in Russia's Don River Basin, by the Dnestr River in Ukraine, and in western Kazakstan that can be traced back several centuries.
A tourist attraction?
General Vlasov hopes these new Cossack units will be better received by the public than the resurrection of the czarist-era Gorodoviye patrols in St. Petersburg.
Brought back in 1997 as a special force to help tourists, the Gorodoviye have become the recipients of local jokes, derisively called "Little Red Riding Hoods" because of their red military hats.
It will be a different case with the Cossacks, asserts Vlasov, who acknowledges a certain bias because he is married to a Cossack woman. He says their dignified, manly presence will particularly impress tourists, who are drawn by the history of this graceful canal city.
"Yes, they will not be bad for tourism," he muses. "I think the tourists would like them."