Bitcoin network comes into existence with Satoshi Nakamoto mining the genesis block (block number 0) of Bitcoin.

Embedded in the coinbase of this block, which can contain any arbitrary data, was the text:
The Times 03/Jan/2009 Chancellor on brink of second bailout for banks.
 

The text refers to a headline published on the 3rd January 2009 in The Times, and is considered both a timestamp of the genesis date and a “dig” at the financial system instability at that time caused by Fractional-reserve banking.