Revolutions of 1848 in the Austrian Empire even socialist currents resisted the Empire's longstanding conservatism. The events of 1848 were the product of mounting social and political tensions after the Congress of Vienna of 1815. During the "pre-March" period, the already conservative Austrian Empire moved further away from ideas of the Age of Enlightenment, restricted freedom of the press, limited many university activities, and banned fraternities. Conflicts between debtors and creditors in agricultural production as well as over land use rights in parts of Hungary led to conflicts that occasionally erupted into violence. Conflict over organized religion was pervasive in pre-1848 Europe. Tension came both from within
2,500 year celebration of the Persian Empire to what they were originally for. The dedicated Shahyad Tower remains as a major landmark in Tehran, although it was renamed Azadi Tower in 1979. 2,500 year celebration of the Persian Empire The 2,500 year celebration of the Persian Empire (), officially known as The 2,500th year of Foundation of Imperial State of Iran (), consisted of an elaborate set of festivities that took place on 12–16 October 1971 on the occasion of the 2,500th anniversary of the founding of the Imperial State of Iran and the Achaemenid Empire by Cyrus the Great. The intent of the celebration was to