Alaeddin Pasha (also known as Alaeddin Bey or Alaeddin Pasa) was the brother of Orhan Gazi, the second ruler of the Ottoman Empire. He was born around 1290 AD to Osman Gazi, the founder of the Ottoman Empire, and his wife Rabia Bala Hatun.
Alaeddin Pasha played an important role in the early years of the Ottoman Empire, serving as a trusted advisor and military commander to his brother Orhan Gazi. He was known for his wisdom, bravery, and administrative skills, which earned him the respect of his brother and the Ottoman nobles.
One of his most notable contributions was his role in the conquest of Bursa, which became the capital of the Ottoman Empire in 1326 AD. Alaeddin Pasha was instrumental in the siege and capture of the city, and he was rewarded with the title of "Pasha" (meaning "high-ranking official" or "lord") by his brother Orhan Gazi.
Alaeddin Pasha also played a key role in the administration of the Ottoman Empire, helping to establish a centralized government and a system of taxation. He was also known for his patronage of scholars and poets, and his court attracted many learned men and intellectuals.
Finally, and perhaps most importantly, the organization of the military received a complete overhaul. Alaeddin proposed that the military be divided into subsets, and an officer be placed in control of each section. This organization seems extremely simple, which leads to the conclusion that before this, there was no control over the army. Also, Alaeddin proposed that a contingent of foot soldiers be instituted that could be summoned in war time to fight. These soldiers, when instituted, had no training and the idea failed. Later on, this failed idea was replaced by the Janissary Corps, but there is no evidence that Alaeddin had anything to do with the development of the janissaries.
In addition to his participation in Ottoman Empire state affairs, Alaeddin seems to have led a very pious, quiet life. He had several mosques built. The Alaeddin Bey Cami in Bursa, completed in 1335, is a typical example of the single unit mosque. It is very advanced architecture, with 8.2 square meters and a three-bay portico. The dome is supported by Turkish triangles and there is a single minaret. Accordingly, the "near perfection of the (Alaeddin Bey) Bursa Mosque lies in the simplicity of which an ideal space is expressed" (Goodwin 18). Although, now after having undergone restoration in the 19th century, the east and west windows are no longer directly across, but slightly askew. The minaret, if it is the original, is the first example of a minaret, but due to architectural weaknesses brought on by the placement of the minaret, it is very likely a later addition.
Alaeddin Bey died in 1331 or 1332 and is buried in Bursa. He lies in the Osman I's imperial türbe in Bursa, built by his brother Orhan.