Short answers, pulled from the story.
The Ottoman Empire ended on the 17th of November 1922 when the last Ottoman Sultan Mehmed VI departed Constantinople. This departure marked the end of an empire that had existed since 1299 and shattered the political consciousness of the Muslim world.
Hassan al-Banna founded the Muslim Brotherhood in 1928 in Ismailiyah, Egypt. The organization adopted the motto the Qur'an is our constitution and became the first large modern Islamic political and religious group.
Sayid Qutb formulated a radical ideology known as Qutbism during the 1950s and 1960s that urged a two-pronged attack of preaching and offensive jihad. His ideas were disseminated by later generations including Abdullah Yusuf Azzam and Ayman Al-Zawahiri to normalize offensive jihad among followers.
Ayatollah Ruhollah Khomeini implemented the Velayat-e Faqih system during the Iranian Islamic Revolution of 1978 to 1979. This system placed the leading Islamic jurist in absolute authority over all individuals and the Islamic government.
The United States spent billions of dollars to aid the mujahideen Muslim Afghanistan enemies of the Soviet Union from the 1950s through the 1970s. This strategy backfired as international volunteers like Osama bin Laden returned home with weapons and ideology to target the United States and other governments.
The term Islamism reappeared in English usage during the Iranian Islamic Revolution of 1978 to 1979. It had virtually disappeared from English usage by 1938 when Orientalist scholars completed The Encyclopaedia of Islam.