The Social Democratic Workers' Party of Germany was founded in 1869 under the influence of Marx and Engels. In 1875, it merged with the General German Workers' Association of Ferdinand Lassalle to become what is known today as the German Social Democratic Party (SPD).
https://en.wikipedia.org/wiki/History_of_socialism
The caliphate of Córdoba was a success because Muslims, Jews, and Christians got along as a result of the Islamic leaders who were tolerant of other religions. Students could extend these arguments by presenting their arguments in an interfaith dialogue about the history of Al-‐Andalus.
There were multiple causes for the Greek War of Independence. Nationalism was spreading and the Greeks wanted their own independent government. The Ottomans were suppressing the Greeks because they were the minority so the Greeks wanted a change. They also wanted Christianity.