Crimean Tatars: Crimean Tatars recall mass exile
Some 200,000 Crimean Tatars were accused by the then Soviet dictator Joseph Stalin of collaborating with the Nazis and exiled to Central Asia.Half died during their journey and many more in their new homeland.
The rally was staged at a train station in Simferopol, where the deportations were carried out in 1944.
Security in the Crimean capital had been stepped up because of recent tensions between the Tatars, who are Muslim, and Ukrainians and ethnic Russians, who are mainly Orthodox Christian, the BBC's Helen Fawkes in Simferopol says.
Crimean Tatar leaders appealed to people to mark the anniversary peacefully and remember the victims with dignity.
Wearing black ribbons and carrying their traditional flags, tens of thousands of Crimean Tatars gathered for the rally to remember those who died.
The main rally was held at the city's Lenin Square.
"The deportation of the entire nation was among the greatest crimes against humanity," Crimean Tatar leader Mustafa Dzhemilev told the flag-waving crowd.
Since the late 1980s some 260,000 Tatars have returned to Crimea - an autonomous republic which became part of Ukraine in 1956. However, they are still a minority on the peninsula, making up only about 12% of the population.
Many of them complain that they face higher unemployment than the majority Slavic population of Crimea, and that the central government in Kiev has not helped them to fully integrate into the new society.
While about half of Crimean Tatars have been allocated land, many also claim they have not been given the prime plots which they believe they have a right to.