While it is hardly any comfort to their victims, the two people most associated with mass deaths in this bloodiest of human centuries -- Adolf Hitler and Joseph Stalin -- were likely surpassed by a third, China's Mao Zedong.
Mao launched more than a dozen campaigns during his rule, which began when he founded Communist China in 1949 and ended with his death in 1976. Some are well known while others, such as a bloody campaign to "purify class ranks" in the late 1960s, which involved army units, have received little publicity.
While most scholars are reluctant to estimate a total number of "unnatural deaths" in China under Mao, evidence shows he was in some way responsible for at least 40 million deaths and perhaps 80 million or more. This includes deaths he was directly responsible for and deaths resulting from disastrous policies he refused to change.
One government document that has been internally circulated and seen by a former Communist Party official now at Princeton University says that 80 million died unnatural deaths -- most of them in the famine following the Great Leap Forward. This figure comes from the Tigaisuo, or the System Reform Institute, which was led by Zhao Ziyang, the deposed Communist Party chief, in the 1980s to study how to reform Chinese society.
In comparison, Hitler is blamed for 12 million concentration camp deaths and at least 30 million other deaths associated with World War II, while Stalin is believed responsible for between 30 million and 40 million "unnatural deaths," including millions from a famine he created.
There are important reasons for the wide discrepancy in the Chinese estimates. During critical periods, records were either kept secret or not kept at all. In many parts of China, the leadership still refuses to open records. In the early years under Mao, many Western scholars were so enamored with Mao that they refused to believe such widespread atrocities could have been carried out by the Chinese Communists.
LAND REFORM CAMPAIGN
1949 TO EARLY 1950s
* The first people to die violently after 1949 were landowners killed in the land reform campaign of the early 1950s. To destroy the power base of the old landlord elite in the countryside, the regime ordered security police to arrange "people's tribunals" to target at least one landlord in every village. Sinologists say at least 1 million people were killed; perhaps as many as 4 million died.
DRIVE TO 'SUPPRESS COUNTERREVOLUTIONARIES'
* At a minimum, tens of thousands of people were executed in a search for potential counterrevolutionaries and Nationalist Chinese sympathizers; some scholars say a million or more died.
* Throughout this period, the Communists launched an attack on the Christian church and other religious groups. While researcher James T. Myers of the University of South Carolina says it is impossible to know exactly how many Christians were targeted for death, certainly many thousands lost their lives.
CAMPAIGN TO 'ELIMINATE COUNTERREVOLUTIONARIES'
* Mao declared that "95 percent of the people are good," leading the party to target 5 percent in many organizations as "bad elements" who should be purged and repressed. At least hundreds of thousands died.
THE GREAT FAMINE
* The greatest loss of life came in the Great Famine, a result of Mao's misguided industrialization effort called the Great Leap Forward. The Chinese government over the years has given varying estimates of deaths and at one time blamed them on the weather. For years many scholars said 20 million died. But Judith Bannister, a demographer at the U.S. Census Bureau, has put the toll at about 30 million. Using material contributed by China's State Statistical Bureau as well as China's State Family Planning Commission, she and other demographers employed complicated formulas involving birth rates before and after the period to reach their conclusion. An even higher figure -- 43 million -- is now gaining some academic currency. Chen Yizi, a former Chinese official now at Princeton University's Center for Modern China, spent years researching the subject in China. He conducted a county-by-county review of deaths in five provinces and, by extrapolation, arrived at 43 million. A research center in Shanghai recently reached the same figure for the number of famine deaths.
THE CULTURAL REVOLUTION
* Mao's movement to destroy his adversaries, counter "bureaucratism" and create a new society. Assessing the figure presents problems; in many places, fighting among Red Guard factions erupted and government and police authority collapsed. Many were tortured or driven to suicide. There have been wild fluctuations on death estimates -- from hundreds of thousands to 20 million. Relying on official Chinese sources, some Western scholars have long accepted that half a million people died in the Cultural Revolution. Hu Yaobang, former communist Party chief, has been quoted as saying that 1 million people died during the period, but the figure apparently excludes the fighting between Red Guard and army factions. A number of scholars, including Harry Harding of the Brookings Institution, believe about 1 million died. But as new evidence emerges, an even higher toll is likely. Two of the Cultural Revolution campaigns least known in the West and least studied by scholars -- the "purification of class ranks" (1968-70) and the campaign against "May 16 elements"(1968-69) -- are now revealed to be among the bloodiest.
OCCUPATION OF TIBET
* During the many campaigns, the occupation of Tibet continued, exacting a horrific price on the people and land. China invaded in 1950. After an uprising in 1959, experts say the Chinese emptied monasteries and threw hundreds of thousands of people into prison camps. The Tibetan government in exile estimates that 1.2 million people have died under Communist rule as a result of war, starvation and repression. Some analysts say this is too high; others believe it is possible. According to the late Panchen Lama, a high-ranking official in the Chinese hierarchy, 10-15 percent of the Tibetan population was initially imprisoned following the 1959 uprising. If there were then 4 million Tibetans, that would be 400,000 to 600,000 people imprisoned. The Panchen Lama estimated about 40 percent died while in prison; other estimates range up to 90 percent. If 40 percent died, the total for Tibet would be 160,000 to 240,000 -- and that is just among those who died in prison during that short period. Tenzin Choedrak, the Dalai Lama's physician said that in a camp where he was held for two years, more than half the prisoners died of starvation.