The Second Constitutional Era (; ) was the period of restored parliamentary rule in the Ottoman Empire between the 1908 Young Turk Revolution and the 1920 retraction of the constitution, after the dissolution of the Chamber of Deputies, during the empire's twilight years. Alternative end dates for era include 1912 or 1913.

The rule of Sultan Abdulhamid II had been opposed by the Young Turks, an underground movement of reformists which called for the restoration of constitutional monarchy. In 1908, a faction within the Young Turks called the Committee of Union and Progress (CUP) forced Abdulhamid II to restore the liberal constitution of 1876 and the General Assembly in the Young Turk Revolution. Abdulhamid II had previously suspended the parliament and constitution in 1878, two years after they had been introduced. Whereas the short First Constitutional Era lacked political parties, the second era initially featured unprecedented political pluralism within the empire and openly contested elections.

The period was marked by political instability as opposition groups attempted to challenge the CUP's dominance and its increasingly repressive tendencies. In 1909, the CUP was briefly expelled from Constantinople (Istanbul) during the 31 March incident, a reactionary uprising sparked by a mutiny of soldiers from the city's garrison. In the aftermath of the crisis, Abdulhamid II was deposed and his brother Mehmed V appointed sultan. The second largest party, the Freedom and Accord Party, remained locked in a power struggle with the CUP and following electoral fraud by the CUP in the 1912 general election its military wing launched a successful coup in July 1912. The CUP regained power in a coup the following year and repressed other opposition parties, effectively establishing a one-party state led by the "Three Pashas", Talaat Pasha, Enver Pasha, and Cemal Pasha.

The empire was in a perpetual state of crisis as it suffered continual territorial losses: Bulgaria declared independence, Austria-Hungary annexed Bosnia and ethnic conflict in Ottoman Macedonia continued unabated. Italy invaded Ottoman Tripolitania in 1911 and the empire lost the vast majority of its remaining European territory when the Balkan League overran Rumelia in 1912. In 1914, the Ottoman Empire entered World War I and the increasingly radicalised CUP conducted ethnic cleansing and genocide against the empire's Armenian, Assyrian, and Greek citizens, events sometimes collectively referred to as the Late Ottoman genocides. Following the Ottoman surrender in 1918, the CUP leadership fled into exile and the Allies occupied Constantinople. The Ottoman Parliament angered the Allies by signing the Amasya Protocol with Turkish revolutionaries in Ankara and agreeing to a Misak-ı Millî (National Pact). As plans for the partition of the Ottoman Empire advanced following the Conference of London, the Allies forced the dissolution of the assembly, thus bringing the Second Constitutional Era to an end. Many parliamentarians would become members of the Grand National Assembly during Turkey's War for Independence, and ultimately continued their careers in the Republic.

Background A consequence of the French Revolution and the Napoleonic wars was popularisation of ideas such as nationalism and nation states, which made multi-cultural countries and empires increasingly difficult to appear legitimate to minority ethnic groups. The Ottoman Empire was no exception to this wave of nationalism, and its Christian subjects would especially start to rise up to demand full independence. These demands for independence by Christians who did not identify with Ottoman rule would therefore turn the Empire's previously multicultural society upside down, creating cycles of violence and suspicion between neighbors.

To solve the many problems the Empire was facing the Tanzimat reforms (1839–1876) were undertaken not only to modernize the Ottoman Empire, but also to build a cohesive Ottoman national identity centered around national pride in the House of Osman rather than in an ethno-religious group. Another problem facing the Empire was that its Christian subjects achieved significant economic advancement in contrast to its Muslim subjects due to external patronage from the European powers, which Muslims were not given access to. Therefore, centralization and economic nationalism were also key goals of Ottomanism and Tanzimat, not only in create equality for all under the law by consolidating previously autonomous sections of society such as abolishing the outdated Millet system, but also to empower the government to redistribute wealth and opportunity to its Muslim subjects.

Abdulhamid II ascended to the throne in 1876 at the height of this period of reform in the Ottoman Empire. One of his first acts as Sultan was transforming the Ottoman Empire into a constitutional monarchy with the introduction of a constitution, thus starting the Empire's first short experience with democracy: the First Constitutional Era. However, in the aftermath of Russian invasion in 1877–1878, following criticism of his handling of the war, Abdulhamid used his constitutional power as Sultan to suspend parliament and the constitution. He instead went on to rule as an autocrat (istibdâd as marked by contemporaries, although many expressed longings for his old-fashioned despotism a few years into the new regime), emphasizing the empire's Islamic character and his position as Caliph.

To many in the empire, the war against Russia in 1877–78 was traumatic. The Russian army almost captured Constantinople (İstanbul) and the war also saw the expulsion and massacres of many Balkan Muslims. The resultant 1878 Treaty of Berlin established the independence of many Balkan nations and the loss of the Caucasian vilayets. When the Empire declared bankruptcy in 1881 the Ottoman economy came under the control of the Ottoman Public Debt Administration, an institution controlled by the European powers and designed to manage the Empire's finances. Though the justification of the Hamidian autocracy was so that the empire won't collapse, many found it hypocritical of Abdulhamid to be content with foreign pressure by conceding sovereignty, land, and the economy to western powers.

The combination of European control over Ottoman finances and Ottoman Christian domination in the Ottoman economy resulted in much anti-Christian xenophobia in its Muslim subjects. Ottoman Christians, especially Ottoman Armenians, started to increasingly feeling insecure in their position as Ottoman subjects after these sentiments manifested in the Hamidian massacres (1894–1896), and started demanding autonomy from the government.

It was in this context the Young Turks movement formed as a loose coalition of elements in the empire opposed to Sultan Abdulhamid II's absolutism. Held together by a common belief in constitutionalism, they argued that the codification of secular law in the Ottoman Empire would foster a sense of Ottoman nationalism and prevent ethnic conflict, helping the empire to hold on to its remaining Balkan territories. The coalition between the Armenian Revolutionary Federation and the Committee of Union and Progress remained essential to the Ottoman reform programme after the constitution was restored, particularly regarding security and the agrarian question in the eastern provinces of the empire.

Young Turk Revolution (1908)

The Young Turk Revolution began with a small insurrection of Committee of Union and Progress (CUP) supporters in Macedonia and spread quickly throughout the empire. The multiethnic vilayets in Macedonia for years faced a collapse of authority and were going through an ethnic conflict known as the Macedonian Struggle. This made recruitment to revolutionary societies like the CUP promising to reform the system attractive to army officers stationed in the region. Unable to regain control of the province, Sultan Abdulhamid II announced the restoration of the 1876 constitution, reconvening the parliament on 23 July 1908. After the revolution, power was informally shared between the palace (Abdulhamid), the Sublime Porte, and the CUP, whose Central Committee was still based in Salonica, and now represented a powerful deep state faction.

As in 1876, the revived Ottoman Parliament consisted of two chambers: a Senate (upper house) and a Chamber of Deputies (lower house). The Chamber of Deputies was elected by the people, in the ratio of one member for every 50,000 males of the population over the age of 25 who paid taxes. Senators, on the other hand, were nominated for life by the Sultan, had to be over 40 years of age, and their number could not exceed a third of the membership of the Chamber of Deputies.

General elections were to take place every four years. The general population did not, however, vote directly for the Deputy that he desired to represent him in the Parliament. In each of the 15 electoral districts, registered voters were entitled to choose delegates in the proportion of 1 delegate for 500 voters, and these delegates (elected Administrative Councils) had the actual power of choosing the representatives in the Chamber. Moreover, the administration of territories was entrusted to these delegates in the elected Administrative Councils. Thus, these Councils were elected and served not only as an electoral college, but also as a local government in the provinces and districts (Turkish: vilayets).

Initial reopening (1908–1909)

With the reestablishment of the constitution and parliament, most Young Turk organizations turned into political parties, including the CUP. However, after meeting of the goal reinstating the constitution, in the absence of this uniting factor, the CUP and the revolution began to fracture and different factions began to emerge. The Liberal Young Turk faction led by Mehmed Sabahaddin founded the Liberty Party and later in 1911 the Freedom and Accord Party. The Liberty Party was liberal in outlook, bearing a strong British imprint, and closer to the Palace. Although the CUP collaborated with the Liberals, their respective goals contrasted strongly. Liberals favored administrative decentralization and European assistance to implement reforms and also promoted industrialization. Ibrahim Temo and Abdullah Cevdet, two original founders of the CUP, founded the in February 1909. Ahmet Rıza who returned to the capital from his exile in Paris became president of the Chamber of Deputies, the parliament's lower house, and gradually distanced himself from the CUP as it became more radical.

It was after the Young Turk Revolution that the first organized labor disputes turned into strikes in the cities of Adrianople, Constantinople, and Smyrna. The motivation of these strikes came from dissatisfaction of the Young Turks' unfulfilled promises to improve worker's rights, which led to a ban on most forms of workers strikes and establishment of trade unions.