I am not an expert but I know enough to give an overview of the people and events involved in the collapse of the Ottoman Empire -

Abdul Hamid II was the Sultan from 1876 until 1909. Abdul Hamid II's rule was not ideal from the start, the Bosnia and Herzegovina uprising started in 1875, the Bulgarian April Uprising in 1876 and the Serbian-Ottoman War in 1876. This lead to the Constantinople Conference where the Great Powers of Britain, France, Austria-Hungary, Germany and Italy travelled to Constantinople to discussed reforms in the Balkans to help stabilise the region. However the Ottoman government and the Great Powers did not agree on the proposed reforms and eventually the Ottomans rejected the proposals. This helped trigger the Russo-Turkish War.

The Russians were still angry about the loss to the Western-backed Ottomans in the Crimean War but were politicaly isolated from most of Europe and restrained by the conditons of the Paris Peace Treaty of 1856 (the peace agreement at the end of the Crimean War). The unrest in the Ottoman Empire, the failure of the Constantinople Conference and the anti-Ottoman sentiment that the handling of the Bulgarian Uprising inflamed, gave Russia the perfect excuse to intervene in the Ottoman Empire's interests and Austria-Hungary, the other influential power in the region, agreed to not stand against Russia. The details of the war are going to far away from the original question so suffice to say that the Ottomans collapsed and suffered a bad defeat, where they were forced to make Bulgarian a principality and recognise the lasting independence of Serbia, Montenegro and Romania. This peace agreement was called the Treaty of San Stefano and was signed in 1878. This helped to lead to Britain sending in troops to Egypt in 1878 to maintain order (effectively bringing it under British rule) and the unification of Bulgaria in 1885 which was another serious blow for the Ottomans in Europe.

Internally this period of Ottoman history (1876-1878) is referred to as the First Constitutional Era. After the failure of the Constantinople Conference the man sent to reject the Great Power's terms was Midhat Pasha. He was a constitutionalist and a member of the Young Ottomans who argued for equal rights without distinction of race or religion, introduction of democracy, abolition of slavery, a stronger civil law code and more. The Young Ottomans were a group of mainly Western-influenced intellectuals who wanted liberal or democratic reform informed by Muslim ethics and tradition. Ideas like "Ottomanism" are very similar to the egalitarian arguments of the Enlightenment. Again I can't go into all the details but their relevance here is that the work of people like Midhat Pasha and Namik Kemal helped to inform the demands that were being made of the Sultans, especially as the Ottomans began to become less and less able to operate without the consent or backing or European powers.

Midhat Pasha was actually something of a kingmaker in the 1870s; leading a coup against Sultan Abdulaziz to install Murad V in May 1876, a candidate sympathetic to the Young Turks, only to assist in deposing Murad for his brother Hamit Efendi (who became Abdul Hahmid II) only three months later. The reason given for deposing Murad was that had apparently lost mental competency after the alleged suicide of Abdulaziz, the Sultan he had deposed. Whether Abdul Hahmid II would have carried through the reforms the Young Ottomans hoped for is uncertain as the events he was forced to deal immediately on becoming ruler forced ideas about reform to take a backseat to attempting to maintain the territorial integrity of the Empire. And although the Sultan did introduce the Ottoman constitution of 1876, partly written by Midhat Pasha (now Grand Vizier) it is hard to judge if this was just being done to try and avoid European powers feeling justified in interfering in the Ottoman’s internal affairs. Once the parliament was founded it was basically ineffectual and the Sultan eventually got rid of it entirely. To further consolidate power in the Sultan and away from intellectuals he banished Midhat Pasha, the man who had helped put him on the throne. Although this was unpopular outside of the Empire, some people who previously supported Pasha turned on him once they learned just how liberal his reforms were in regards to religion. It’s possible that Abdul Hamid II was still sympathetic to the Young Ottomans ideas but thought they were impossible/needed to be handled carefully, but it’s also possible he simply used the Young Ottomans for his own purposes and got rid of them at the first chance. In either case what he did was return to ruling with basically absolute power.

Due to international pressure Midhat Pasha was allowed to return to the Empire and became Governor of Syria where he ruled in accordance with his ideas. However in 1881 he was charfed with the murder of Abdulaziz (the Sultan who was alleged to have committed suicide). He was found guilty in a suspect manner but his execution was stayed due to pressure from the British. Eventually he died in a suspicious accident, extra suspicious as it meant the Sultan could say they had co-operated with the British the whole time while still getting what he wanted.

The Empire’s relationship with most of the European powers didn’t really recover, especially in the case of the alliance of Britain, France and Russia (who would form into the Triple Entente between 1894, when France and Russia allied, and 1907 when the Anglo-Russian aggrement was signed to settle many of the two powers differences). Similar to Germany in many ways the Ottomans felt marginalised and not taken as seriously as they should be, not one of the Global Powers. As mentioned Britain essentially seized Egypt under false pretences in 1878 and similarly France essentially seized Tunisia as a protectorate in 1881 under similarly questionable circumstances (an accusations of Tunisian troops crossing the Algerian border). In 1885 the unification of Bulgaria happened. When the Greeks invaded Crete in 1889 they were beaten but the Ottomans victory was short-lived because by 1908 the Cretan nationalists had regained power and united with Greece. In the 1890s there were attacks against Armenians began after Armenians began demanding more reforms, these "Hamidian massacres" further soured European opinion against the Ottomans.

An important group was the successor of the Young Ottomans (who Abdul Hahmid has allied with and then betrayed early in his reign), the now famous Young Turks. The Young Turks ideological origins lie with the Young Ottomans. Wanting much the same as what Midhat Pasha outlined in the 1870s. The Young Turks and other exiles and revolutionaries began organising meetings in European countries in 1902. In 1906 the Committee of Union and Progress (CUP) essentially became the political party of the Young Turks. The CUP basically argued that the Ottoman empire needed some liberal reform and to modernise, but could do so without being enthralled to Western powers or losing their Ottoman/Muslim identity. Although there is lots of debate about the word I’d say describing them as nationalists would be fairly accurate. As well as ideas for reform there was heavy criticism by people living in exile, describing him as a tyrant. Ahmed Riza said that the Sultan was a "cheat, hangman, scourge of God, bloody majesty, bloody despot, degenrate tyrant, disgrace of the Mussulmans, wolf guarding the sheepfold...a red sultant" in a Ottomon-French journal. As well as the Young Turks there were other factions who opposed the Sultan. Prince Sabahaddin was a notable example. He was actually part of the ruling house of the Ottoman Empire, the Osmans. In 1899 he fled along with other members of his family (also liberals) to Europe and continued calls for reform. More on this later.

Meanwhile outside the Ottomoan Empire Britain and Russia were both still engaged in the so called Great Game of war and diplomacy around Afghanistan where the two power's sphere of influence met. In 1905 the Persian Revolution gave Britain and Russia common ground, neither wanting liberal democratic reforms to spread in the region as it was considered that would be damaging for the interests of the two powers. So they decided to come to an agreement of how to split up Iran in the mutual interests of both powers. This agreement is called the Anglo-Russian-Convention and was completed in 1907. This agreement caused further unrest in the Ottoman Empire as it was Russia and Britain slicing up a country that was deemed too troublesome to be tolerated, right on the Ottoman's doorstep. The Ottoman's of course having their own problems with internal unrest and the spreading of "dangerous" ideas, so maybe it would be Ottoman territory getting divided up next? In the Ottoman armed forces many did believe the wolves were at the door at that the Sultan either could not or would not stand up to Russia and Britain. Combined with the existing tensions and demands for reform this was a recipe for revolution. With the armed forces not being sympathetic to the Sultan there was little he could do and within a month the Sultan surrendered and restored the 1876 constitution. This is known as the Young Turk Revolution and the begining of the Second Constiutional Era.

Ok so I'm approaching the character limit and this is taking longer than I thought. So let's call this part 1 and I'll write up the rest when I next have some free time, which will almost definitely be tomorrow or Sunday morning. The main things I still want to cover are what happened after the revolution, the Balkan League, The Three Pashas and Mustafa Kemal Ataturk. Oh and how the relationship with Germany developed. Leave any questions about what I've already said and I will answer them too.