Complex sentence: Rentzias was a member of the Greek national basketball team from 1994 to 2002 and competed in the 1996 Olympic Basketball Tournament at Athens, marking the first ever appearance by Greece's men's basketball team in a Summer Olympics.
Split into simpler sentences: Rentzias was a member of the Greek national basketball team from 1994 to 2002 and competed in the 1996 Olympic Basketball Tournament at Athens. That was the first ever appearance by Greece's men's basketball team in a Summer Olympics.