Blockstream developer, Christian Decker completed the world's first lightning network transaction

The first Lightning Network transaction on the main net took place on May 10, 2017, and it was a significant milestone for Bitcoin’s scalability. The transaction was initiated by Blockstream developer Christian Decker. Interestingly, this transaction did not occur on Bitcoin’s main chain but on Litecoin, a popular fork of Bitcoin. This was common practice at the time since Litecoin shared much of Bitcoin’s source code, with minor changes such as faster block times and a larger total issuance.
 

The transaction was important because it demonstrated that the Lightning Network, a second-layer solution, could successfully operate on Bitcoin. The transaction was for a mere 1.3 US cents, which would normally not be possible on Bitcoin’s main chain due to the fees being too expensive. This inexpensive transaction being economically feasible opened up new possibilities for types of transactions within the Bitcoin ecosystem.
 

The success of this transaction proved that the Lightning Network could enable faster and cheaper transactions, paving the way for Bitcoin to scale and accommodate a larger number of transactions, which is crucial for its widespread adoption as a digital currency.