The first Bitcoin halving occurred on November 28, 2012. Bitcoin halving is a significant event that happens approximately every four years as a fundamental part of the cryptocurrency's monetary policy. During a halving, the reward that miners receive for validating and adding new blocks to the blockchain is cut in half. This mechanism is embedded in Bitcoin's code to control its inflation rate and ultimately limit the total supply of Bitcoin to 21 million coins.

In the case of the first halving, the block reward was reduced from 50 bitcoins per block to 25 bitcoins per block. This event marked a crucial milestone in the development of Bitcoin, as it emphasized its deflationary nature and scarcity. The halving events also tend to have a considerable impact on Bitcoin's price and market dynamics, as the reduction in new supply entering the market can create supply-demand imbalances.

The first halving not only demonstrated the effectiveness of Bitcoin's built-in monetary policy but also solidified the concept of halvings as anticipated events that shape the cryptocurrency's trajectory. Subsequent halvings occurred in 2016 and 2020, further reducing the block reward to 12.5 and 6.25 bitcoins per block, respectively. These halvings play a pivotal role in understanding Bitcoin's economics and its journey towards becoming a digital store of value.