Let’s look at important dates in the development of blockchain technology.
Some people believe that Bitcoin magically appeared back in 2009. This is not the case. We have to look way back to 1991. Stuart Haber and W. Scott Stornetta were the ones who invented the concept of blockchain technology.
Here is the link to their academic paper: https://www.anf.es/pdf/Haber_Stornetta.pdf
This paper explains the foundations of blockchain, a cryptographically secured chain of blocks.
The next step towards the launch of the first blockchain and Bitcoin came from Nick Szabo in 1998. He created the concept of bit gold, which was a decentralized digital currency. He also developed the concept of smart contracts. Smart contracts are either a computer program or transaction protocol which intends to automatically execute or control and document legally relevant events and actions according to the terms of a contract. This is a very sophisticated way to say when the conditions of A is met, B can be done or distributed.
In 2000, Stefan Konst published the theory of cryptographically secured chains, plus his take on implementation. Finally, in 2008 a developer or group of developers working under the name Satoshi Nakamoto released a whitepaper establishing the model for the blockchain. This is the holy grail, which outlines what blockchain technology can accomplish. https://bitcoin.org/bitcoin.pdf