The Sultan Saladin (otherwise spelt 'Salahuddin', full name An-Nasir Salah ah-Din Yusuf ibn Ayyub) Ayubi (1137-1193) was the brave ruler of a Muslim army hence why he is known as the 'Noble Prince of Islam'.
1. Capture of Egypt 1164-1171
In 1164, Asad al-Din Shirkuh (Saladin's uncle and a large Kurdish general who was blind in one eye) led a campaign into Egypt under the instructions of Nur ad-Din (Emir of Damascus and Aleppo). Though Shirkuh and Nur ad-Din shared trust within the same inner circle, Shirkuh wanted to establish his own independent power for his Ayyubid clan. Therefore, Shirkuh and his 26 year old second-in-command, Saladin, fought several campaigns in the Nile region. When King Almaric of Jerusalem failed four invasions into Egypt, he was forced to retreat making the pathway clear for Shirkuh who became ruler of Egypt after ordering the assassination of the Egyptian vizier, thus uniting Syria and Egypt. Saladin succeeded Shirkuh a few weeks later when Shirkuh died from a heart attack. Saladin imposed Sunni Islam onto the region by building Sunni madrasas and dismissing Shia judges. Saladin also established the Salahiyya (his own military corps). The benefit of capturing Egypt was that Saladin accessed the vast Egyptian wealth, he could also encircle the Crusader States by uniting Syria and Egypt, thus increasing the chances of recapturing Jerusalem (as he did shortly after - see event number 4) and could defeat his Muslim opposition- the Shia Fatimids. On 10th September 1171, Saladin was no longer vizier of Egypt and second-in-command to Shia Caliph, al-Adid, as he died (potentially poisoned) meaning that Saladin was now in control of Egypt.
2. Conquest of Syria 1174-1183
The death of Nur ad-Din in 1174 and the subsequent weakening of the Zengi regime provided Saladin with the opportunity to establish control in Syria. Saladin did not use force due to the fact that he had pledged loyalty to al-Salih, Nur ad-Din's younger son and had even acknowledged him as Sultan. Instead, Saladin had to use diplomacy and propaganda to capture Syria and build his power. He solidified his legitimacy by marrying Nur ad-Din's widow. In order to tighten his grasp of Syria, he targeted Damascus by protesting that the rulers were weak for signing a truce with the Crusader State of Jerusalem and distributed money across Damascus to help gain the support of the public. This proved to be successful in 1174 when several Syrian warlords accepted him as the ruler. The public supported Saladin due to his achievements in Egypt which had made him popular. Following this, Saladin was able to capture Homs, Hama, and Baalbek with ease but it wasn't until 1183 that he was able to seize control of Aleppo.
3. Battle of Hattin 1187
The infamous battle was triggered when Raynald of Chatillon, Prince of Antioch (one of the four Crusader States), broke a truce he had made with Saladin; Raynold attacked Muslim pilgrims travelling to Makkah which resulted in Saladin starting a war on his own terms against an unprepared Crusader army. The lack of preparation contributed to the Crusaders' failure as they didn't have a sufficient water supply. Saladin manipulated this to his advantage by burning crops in order to scorch the throats of already dehydrated Crusaders in a hot desert; Saladin also filled in wells to remove any source of water the Crusaders could access; he also positioned his troops behind a lake to tempt the thirsty Crusaders to attack. The Crusader's formation suffered because Raymond III, Count of Tripoli, wasn't strong enough as a leader to convince them to avoid the temptation. Saladin further exploited Crusader weaknesses when he captured Raymond's wife and Guy of Lusignan, King of Jerusalem, ignored Raymond's advice to not engage with Saladin and instead pay a ransom in the hopes Saladin would retreat. Moreover, Saladin took away Crusaders' motivation by taking the True Cross - a holy relic that the Crusaders believed would give them God's protection as well as the advantage in the battle. Therefore, Saladin's tactics and manpower (30,000 of his men against approximately 16,000 Crusaders) enabled him to claim a victory in this battle and recapture Jerusalem for Muslims. In the aftermath of the battle, Saladin had captured many Crusaders including Guy and Raynald. Out of generosity, Saladin offered Guy a goblet of water (a sign that their life would be safe) but forbade Guy from giving the goblet to Raynald since Raynald had broken his truce with Saladin. Saladin beheaded Raynald with a sword himself, but let Guy go in 1188 saying 'A king does not kill a king'.
4. Capture of Jerusalem 1187
Due to the fact that the Crusaders used nearly all their manpower to create their army for the Battle of Hattin, there wasn't many people to defend Jerusalem when Saladin came for it in 1187. Nonetheless, despite Jerusalem only having approximately fewer than 14 knights (some estimates vary and suggest there were only 2 knights) to defend it, it still took Saladin and his large army between five-ten days to capture Jerusalem. Saladin swore he would take the city by force only which is what he achieved. He allowed natives to remain but ordered Franks to leave; other citizens that wanted to leave had to pay a ransom and those who couldn't pay were enslaved (although many of these victims were released).
5. Third Crusade and Battle Against Richard the Lionheart 1187-1102
Despite the previous events highlighting Saladin's strength, Saladin finally met his match in the Third Crusade, Richard I of England. Richard won the victory at Acre in 1191 after only one month of fighting despite Saladin starting the attack on Acre in 1187; Richard then slaughtered 2700 Muslims in three days following his victory when Saladin failed to meet the terms of the truce (return 1500 Christians and the True Cross relic). Richard also won the Battle of Arsuf in 1191 against Saladin; despite Saladin starting the battle on his own terms and outnumbering the Crusaders (30,000 to 16,000) Richard was able to maintain tight discipline of his army and force Saladin to retreat. Nonetheless, Saladin filled in all the wells with poison around Jerusalem and destroyed all settlements and fortifications between Jaffa and Jerusalem; this meant Richard and his army had to walk all the way from Jaffa to Jerusalem with no place to stop whilst Saladin simultaneously attacked Richard's vulnerable supply line. Richard desparately sought to convince his army to take Egypt before taking Jerusalem as it was the heart of Muslim power and would leave them too weak and demotivated to defend Jerusalem. His attempts failed. Consequently, the Crusaders withdrew from the expedition without attempting to take Jerusalem. Yet, the Crusaders won certain smaller victories in the Truce of Jaffa 1102 including the ability for pilgrims to access Jerusalem for free for three years as well as keeping all the ports they captured along the way but Saladin remained in control of Jerusalem. Saladin remained weary of Richard and had even made plans to evacuate Jerusalem if Richard had marched on Jerusalem due to the fact that Saladin saw him as a worthy opponent and his own family was beginning to betray him.
A few months after signing the treaty and reverting Jerusalem into an Islamic sphere, Saladin died of fever in Damascus in 1193.
References:
Byrom, J. and Riley, M. (2013). The Crusades, Hodder Education, Hachette UK Company, Carmelite House, London
Lyons, Malcolm Cameron. Jackson, (1982). E. P. "Saladin. The Politics of the Holy War" Cambridge University Press
Rickard, J (10 October 2013), Saladin's Conquest of Syria, 1174-1185, History of War