The very first block in the blockchain mined by Satoshi Nakamoto that began it all with hard-coded contents and an all-zero reference to a previous block. Genesis block was released on January 3, 2009 with a newspaper quote in its coinbase : “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks” as proof that there was no secretly pre-minted blocks to overtake the blockchain in the future. The message ironically refers to a reason for Bitcoin existence: a constant inflation of money supply by government and central banks.
Malone, J.A (2015). Glossary of Bitcoin Terms and Definitions. United States: Lulu Press, Inc