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.
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.
Herodotus is considered the father of history. The second ancient Greek historian was Thucydides.
In 622, a significant event known as the Hijra took place, marking the migration of the Prophet Muhammad and his followers from Mecca to Medina (then called Yathrib). This migration was prompted by increasing persecution of Muslims in Mecca and is considered a pivotal moment in Islamic history, as it led to the establishment of the first Muslim community and the foundation of the Islamic state. The year 622 also marks the beginning of the Islamic calendar, known as the Hijri calendar.
In Islamic belief, the first person on Earth is Adam, who is also considered the first prophet. According to Islamic teachings, Allah created Adam from clay and breathed life into him, making him the first human being. Adam's story is central to Islamic theology, highlighting themes of creation, obedience, and the beginnings of humanity. His wife, Hawwa (Eve), is also recognized as the first woman in Islam.
He was the first sultan of Egypt. Not sure of his impact on the feudal system. Question for Egyptian and islamic history.