Complex sentence: In 1966, Belgrave was among a dozen foundation members of the Yarra Valley Mountain District Football League which came about as a result of a merger between the Mountain District Football League and the Yarra Valley Football Association.
Split into simpler sentences: In 1966, Belgrave was among the founding members of the Yarra Valley Mountain District Football League. The league was established as a result of a merger between the Mountain District Football League and the Yarra Valley Football Association.