When 13th century started, Muslims as a whole were in a critical era. At that time a new Empire appeared on the world map. Under the Command of Genghis Khan, when its army from Magnolia attacked on other territories for expansion of its empire then one side, it extended from east Europe to Middle Europe, on other side it reached Siberia, Indo Pak Sub continent, China and Iran were able to assert their power very quickly The oppression and brutality set by Mongol Army was one of its kinds and will remain an example till end of this world. All major kingdoms of the world were breaking away in front of Mongols oppression ۔ On the other hand, Khwarzim Empire had conquered Khorasan, Iran, Syria and many territories of Seljuks in Iraq. At that time they were enjoying their golden era. The hurricane of Genghis Khan along with its all brutalities brutalities moved towards Khwarzim Empire and destroyed it fully. After the destruction of this empire, the Turks tribe who were living there started migrating towards a safer place. Among those most of the tribes were shepherds and Bedouins. Where ever they saw, green area and the water, they camped. From these Turk tribes, some settled in Iran and Syria whereas a few migrated towards Egypt. Among those Turk Tribes, there was a tribe named Kayi. Kayi tribe was bigger and stronger than other tribes. This tribe was full of warriors. Suleiman shah was the leader of this tribe. Kayi tribe under the leadership of Suleiman Shah left their native country Khorasan after wondering around different countries decided to go towards Syria. On the way, while crossing river Euphrates, Suleiman Shah drowned and died Suleiman Shah had 4 sons, Sungurtekin, Gündoğdu, Ertuğrul, Dündar After the death of Suleiman Shah, the Kayi tribe was dispersed. Sungurtekin & Gündoğdu along with their families and many companions went to Ahlat, those who remain, choose Ertuğrul Gazi as new leader of Kayi tribe because of his valour and bravery Ertuğrul Gazi was a brave, fearless, and warrior person who knew best to defend his tribe. So he, along with his younger brother Dündar Bey and around 420 families started his journey towards Asia Minor and entered in Seljuk Empire. During those days, Sultan Alā ad-Dīn Kayqubād I was the ruler of Seljuk Empire who was very famous for his justice. When Ertuğrul Gazi along with his tribe was going to Konya to take refuge under Sultan Alā ad-Dīn Kayqubād I on the way near Ankara he saw two forces fighting each other. He did not know any one of them but by realizing the fact that one force was weak while the other one was stronger, he along with his small group of members which were around 444, decided to help the weak group. and all of sudden he Attacked the opponent army with intensity. The opponent army got scared and realized that they got help from anywhere Being on the verge of victory they lost the battle. Later, Ertuğrul Gazi came to know that the army whom he helped was the army of Sultan Alā ad-Dīn Kayqubād I. There are two points of view regarding the opponent army. Some say that it was the army of byzantine, while majority claim that they were Mongolians. Sultan Alā ad-Dīn Kayqubād I was pleased with the bravery of Ertuğrul Gazi and his tribe was given the area of Karaca Dağ near Ankara in its empire. It was a hilly area. Kayi tribe settled there. It is said that Sultan Alā ad-Dīn had given this area to the Kayi Tribe so that the borders of this side can be protected from the attacks from Byzantines army. Sultan allowed them to conquer the areas along the border and add them to the empire. This area was connected with the Byzantine’s Border. In a very short span of time, Ertuğrul impressed everyone with his bravery. After some time, Söğüt city was also allotted to Ertuğrul Gazi by sultan. The result of these victories was that many other Turkish tribes also joined Ertuğrul Gazi and accepted him as their Chief. Thus the power of Ertuğrul Gazi increased day by day and his influence began to be established in surrounding areas. For a landlord to get such power and influence, could have been a matter of concern for Sultan Alā ad-Dīn but due to internal disorder and rebellions from state chiefs in Asia Minor, the Seljuk Empire was at the last stage of decline. Although the glory of Seljuks was still prominent in Konya but the government’s scope was very limited. On one side, the Mongolians had occupied a large area while on the other, Christian forces had re-occupied many old Byzantines Provinces. Beside this, many Seljuk leaders had established autonomous governments۔ The borders areas were usually in state of war and there was always a threat of attack from Mongols. In such a situation, instead of getting worried from the victories of Ertuğrul Gazi, Sultan had a sigh of relief, so he rewarded to Ertuğrul Gazi. So, at a location between Yeni City and Bursa, as a deputy of Alā ad-Dīn, when Ertuğrul Gazi defeated a united army of Mongols and Byzantines, Sultan rewarded this city as well to Ertuğrul and he named the entire state “Sultanooni”. He also made Ertuğrul Gazi the commander of his front line army troop. In this vast area(Sultanooni), there were numerous castles besides landless pastures and fertile lands. But most of the area of Sultanooni was occupied by stubborn leaders, and in order to fully establish his authority Ertuğrul Gazi and later on his son Osman Gazi had to fight for a long period. In 1281 and according to some others in 1288 Ertuğrul Gazi died at the age of 90. Halime Hatun wife of Ertuğrul Gazi, was the daughter of Seljuk Prince Ghiyāth ad-Dīn Mas’ūd. Halime Hatun gave birth to three sons, Gündüz, Savcı and Osman. After the death of Ertuğrul Gazi, his successor was his youngest son Osman Gazi. Osman Gazi like his father was a true Muslim, Brave and Courageous person. He also continued the series of victories In 1299 when Seljuk Empire was completely over, Osman Gazi announced his autonomous government in all his conquered areas. Thus the Ottoman Empire was established separately from the Seljuk Empire. So a new Empire appeared on the world map which survived for more than 600 years and which extended over 3 continents with an area of around 20 Million square kilometer. If you want to know about each Ruler of this Great Empire, you can watch these documentaries on our channel “Islami Aqdaar” Ertuğrul Gazi was buried in Söğüt, his son Osman Gazi also built a mosque there. The current tomb of Ertuğrul Gazi was re-built in Sultan Abdul Hamid II era. In 1998, Ertuğrul Gazi Mosque was built in his honor in Ashkabad, Turkmenistan province.