At the beginning of the 13th century, Muslims by and large were facing a hard time. In the meantime, a new empire started to spread on the globe. When in the leadership of Genghis Khan a bloodthirsty Mongolian army attacked other areas to spread their empire (Mongol Empire), then on one side, while passing through Eastern Europe they reached Central Europe, while on the other side they proved their power in Siberia, Subcontinent, China and Persian Area very soon. Mongol armies created a noncomparable history of cruelty and oppression. All great empires were bowing their heads to Mongol cruelty. On the other hand, Khuwarzam Empire conquered many areas of Khorasan, Iran, Syria, and Iraq occupied by Seljuks. At that time their power was at its peak. Genghis Khan named Tornado moved towards Kuwarzam Empire with his all cruelties and tor it into pieces. After the wrath of this Empire, Turk tribes residing there started to migrate in search of a safe place. Most of the tribes were shepherds and gypsy, wherever they saw greenery and water they placed their tents there and started living. Most of these tribes reached Iran and Syria whilst some of them migrated towards Egypt.
One of these Turk tribes was named Kayi tribe. Kayi tribe was relatively stronger and a little bit more populated than others. This was a warrior tribe and its leader was Suleiman Shah. Kayi tribe in the leadership of Suleiman Shah left his homeland Khorasan and went to Syria. On his way, while crossing Euphrates river, Suleiman Shah drowned and couldn’t survive. Suleiman Shah had four sons, Sungurtakun, Gundugdu, Ertugrul, and Dundar. After the death of Suleiman Shah, Kayi tribe got separated. Sungutakun and Gundugdu went to Ahlat with his families and companions. Remainders choose Ertugrul as their leader because of his valor and bravery.
Ertugrul Ghazi had a brave, fearless and warrior personality. He knew very well how to defend his tribe that’s why he with his brother and his tribe which was consist of almost 420 families headed towards Asia Minor and entered Seljuk’s Empire. At that time Seljuk throne belonged to Sultan Ala-ud-Deen Kayqubad, who was very famous because of his justice. When Ertugrul Ghazi was going to Capital Konya with his tribe to seek refuge under Sultan Ala-ud-Deen, On his way near Ankara Ertugrul Ghazi saw two armies fighting with each other. Ertugrul Ghazi was familiar with none of the armies, but he whilst watching that one of them is less crowded and the other one is a huge army, he with his smallest army who were totally 420 only, stood with the less crowded ones. He attacked the opponent army with his these few soldiers suddenly and strongly. Opponent army got scared and thought that they might have got some help from somewhere. This army whilst it was winning lost the battle. Later on, it came to know that the army whom Ertugrul Ghazi helped was the army of Seljuk Sultan Ala-ud-Deen Kayqubad.
It is not clear that the opposing army was of whom. Some say that that was the Byzantine’s army and many say that, that was Barbarians Army. Sultan Ala-ud-Deen was very impressed by Ertugrul Ghazi’s bravery 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 the Sultan. The result of these victories was that many other Turkish tribes also joined Ertuğrul Ghazi and accepted him as their Chief.
Thus the power of Ertuğrul Ghazi 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. Besides this, many Seljuk leaders had established autonomous governments۔ The borders areas were usually in a 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 Ghazi,
Sultan had a sigh of relief, so he rewarded to Ertuğrul Ghazi. So, at a location between Yeni City and Bursa, as a deputy of Alā ad-Dīn, when Ertuğrul Ghazi 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 Ghazi 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 Ghazi and later on his son Osman Ghazi 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 Ghazi 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 Ghazi, 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 kilometers.
Ertuğrul Ghazi was buried in Söğüt, his son Osman Ghazi also built a mosque there. The current tomb of Ertuğrul Ghazi was re-built in Sultan Abdul Hamid II era. In 1998, Ertuğrul Ghazi Mosque was built in his honor in Asbghat, Turkmenistan province.