The term "First Megadeath" is not a term typically used either by Muslims, Islamic Scholars, or Islamologists, so there is no answer to the question exactly as written.
If the question is asking more generally as to who Muslims see as the first foreign leader or general to inflict massive human and societal cost on Muslims on the level of millions of dead and irreparable financial catastrophe, this would undoubtedly be HÜLEGÜ KHAN of the Mongol Empire, who smashed the Khwarezmian and Abbassid Empires to the ground and razed the city of Baghdad so completely that it did not gain pre-Hülegü levels of inhabitation until the 20th century.
There was no special color but traditionally black, green etc were used from the early times in Islamic history.
100..........
Bilal bin Rabah
Eid-ul Fitr was and is celebrated on the 1st of the Islamic lunar month of Shawaal, which is the month that comes right after the month of Ramadan.
NovaNET answer: was the first to write a rational history
There was no special color but traditionally black, green etc were used from the early times in Islamic history.
100..........
Bilal bin Rabah
The first person credited with building a prison in Islamic history is Caliph Umar ibn al-Khattab. He established a prison in Medina to detain individuals who committed crimes, reflecting the need for a structured legal system in the early Islamic community. This development indicated a shift toward organized governance and law enforcement within the burgeoning Islamic state.
Eid-ul Fitr was and is celebrated on the 1st of the Islamic lunar month of Shawaal, which is the month that comes right after the month of Ramadan.
NovaNET answer: was the first to write a rational history
Herodotus is considered to be the father of history. Herodotus was the first to record a historical event and that was the Persian War.
Herodotus is considered the father of history. The second ancient Greek historian was Thucydides.
In 622 AD, the Hijra occurred, marking a significant event in Islamic history when the Prophet Muhammad and his followers migrated from Mecca to Medina. This migration was driven by escalating persecution in Mecca and is considered the beginning of the Islamic calendar. The Hijra established the first Muslim community and laid the foundation for the growth of Islam as a religious and political force.
He was the first sultan of Egypt. Not sure of his impact on the feudal system. Question for Egyptian and islamic history.
Hijra is important in Islam as it marks the migration of the Prophet Muhammad from Mecca to Medina. It is considered a turning point in Islamic history, symbolizing the establishment of the first Islamic state. The Hijri calendar also begins with the year of the migration (622 CE), making it significant for Muslims worldwide.
Herodotus is believed to be the first historian in the western world. He's also th father of history.