Kleptocracy
A ruling body or order of thieves.
A government by thieves; a nation ruled by this kind of government.
Hence a government characterized by rampant greed and corruption.
[See also politics, from the words “poly” meaning “many”, and “ticks” meaning “blood-sucking parasites.”]

The first use recorded by the OED is in 1819 although regular use does seem to appear until the late-1960s.