Crimes against humanity, as defined by the Rome Statute of the International Criminal Court Explanatory Memorandum, "are particularly odious offenses in that they constitute a serious attack on human dignity or grave humiliation or a degradation of one or more human beings. They are not isolated or sporadic events, but are part either of a government policy (although the perpetrators need not identify themselves with this policy) or of a wide practice of atrocities tolerated or condoned by a government or a de facto authority.

Murder; extermination; torture; rape; political, racial, or religious persecution and other inhumane acts reach the threshold of crimes against humanity only if they are part of a widespread or systematic practice. Isolated inhumane acts of this nature may constitute grave infringements of human rights, or depending on the circumstances, war crimes, but may fall short of falling into the category of crimes under discussion."

The riots were orchestrated by the Turkish government of the time under the Prime Minister Adnan Menderes. The events were triggered by the false news that the Turkish consulate in Thessaloniki, north Greece—the house where Mustafa Kemal Atatürk had been born in 1881—had been bombed the day before.

The 1961 Yassıada Trial against Menderes and Foreign Minister Fatin Rüştü Zorlu exposed the proximate planning of the riots. Menderes and Zorlu mobilized the formidable machinery of the ruling Demokrat Parti (DP) and party-controlled trade unions of Istanbul. Interior minister Namık Gedik was also involved. According to Zorlu's lawyer at the Yassiada trial, a mob of 300,000 was marshaled in a radius of 40 miles (60 km) around the city for the attacks.

Predictably, the situation came soon out of control and the mobs were shouting "First your property. Then your life".