Young Turk Revolution
The Young Turk Revolution (July 1908) of the Ottoman Empire was when the Young Turks movement restored the Ottoman constitution of 1876 and ushered in multi-party politics in a two stage electoral system (electoral law) under the Ottoman parliament.
More than three decades earlier, in 1876, constitutional monarchy had been established under Sultan Abdul Hamid II during a period of time known as the First Constitutional Era, which only lasted for two years before Abdul Hamid suspended it and restored autocratic powers to himself. On 24 July 1908, Abdul Hamid capitulated and announced the restoration of Constitution, which established the Second Constitutional Era. After an attempted monarchist counterrevolution in favor of Abdul Hamid the following year, he was deposed and his brother Mehmed V ascended the throne.
— Wikipedia article on the Young Turk Revolution