http://www.mining.com/central-bank-gold-buying-surges-50-year-high/

Fifty years ago the price of gold was fully freed from US government control, helping to set off a rapid rise in inflation ending around '79/'80 when central banks became sellers, selling even gold they did not have on hand.  This was an attempt to stem rampant inflation.  That began a long period of declining gold prices to the Turn of the Century.  There is no evidence that a similar cycle is underway now, but it does look probable, at least to me.

I can't find a chart back to '69, but this will do.

VP