Short answers, pulled from the story.
Simko Shikak led an armed uprising against the Qajar dynasty of Persia in 1918. This rebellion lasted until 1922 and involved thousands of Assyrians who were massacred during the conflict.
The Kurdish Democratic Party of Iran established the Republic of Mahabad in 1946 within a small territory including only Mahabad and its adjacent cities. Government forces entered Mahabad unopposed when the Soviets withdrew from Iran in December 1946.
More than 30,000 Kurds died during the 1979 rebellion and subsequent insurgency. The conflict resulted in 10,000 killed and 200,000 displaced before ending in December 1982.
PJAK is affiliated with the Marxist PKK from Turkey though they tend to neglect this relation. One of the first actions of the Obama administration declared PJAK a terrorist organization.
Ethnic Kurds rioted in Mahabad following the unexplained death of Farinaz Khosravani, a 25-year-old Kurdish hotel chambermaid. As of the 11th of May, the death toll rose to six protesters killed according to ARA sources.