Western and europeans in general fought each other a lot resulting in superior fighting tactics. Other places did not do this, giving europe a huge edge against everybody.
Sunni and shia The division into these two denominations of Islam happened after the death of Prophet Muhammad, when there was contention as to who would be his successor. Some people (Sunnis) believed that only someone who is capable enough should be given this responsibility while others believed that the leadership should stay with only members of Prophet's family(Shias).
A. John Jay was the first chief justice of the US Supreme Court. He became that on September 26, 1789, and remained chief justice until 1795.
Members are appointed by president but confirmed by the senate.
