One of the closest companion of the prophet (SAW) and he was critical in spreading Islam in the early and difficult days and he was critical in leading Muslims after prophet (SAW) passed away.
Defeated the two superpowers during his time, which were the Persian and Roman empires. The Prophet (SAW) said if there would have been a prophet after him, it would have been Umar (RA). The Prophet (SAW) also said, if a shaytaan sees Umar (RA) walking down a path, the shaytaan goes on a different path.
The possessor of two lights meaning he was married to two daughters of the prophet (SAW). He is also credited for compiling all copies of the Quran into one standard Quran.
Was taken under the wing of the prophet (SAW) at the age of 6 and was the first non-adult to become a Muslim. He was also the cousin of Muhammad (SAW).