Complex sentence: The George Cross (GC) is the highest civil decoration of the Commonwealth of Nations, although certain Commonwealth Realms have now instituted their own indigenous honours systems, replacing the GC and other Commonwealth awards so far as their citizens are concerned.
Split into simpler sentences: The George Cross (GC) is the highest civil decoration of the Commonwealth of Nations. Although certain Commonwealth Realms have now instituted their own indigenous honours systems, replacing the GC and other Commonwealth awards so far as their citizens are concerned.