Bellatrix Hard Fork Upgrade

    Pathik Bhattacharya
    Pathik Bhattacharya
    Published on October 13, 2022 7:41 PM

    Updated on January 16, 2023 1:42 PM

    In this article we are going to dig a bit deep into Ethereum's famous Bellatrix hard fork upgrade. What is it and how it works.
    Bellatrix Hard Fork Upgrade

    Key Highlights

    • Ethereum Mainnet uses proof-of-stake, but this wasn't always the case.

    • The upgrade from the original proof-of-work mechanism to proof-of-stake was called The Merge.

    • The Merge refers to the original Ethereum Mainnet merging with a separate proof-of-stake blockchain called the Beacon Chain, now existing as one chain.

    • The Merge reduced Ethereum's energy consumption by ~99.95%.


    The final significant update before "The Merge," when the Ethereum network will switch from proof-of-work (PoW) to proof-of-stake (PoS) consensus, is known as Bellatrix.

    In astronomy, Bellatrix is a bluish variable star of second magnitude that, when viewed from Earth, forms the right shoulder of the constellation Orion and ranks third among its brightest stars.

    The same thing Ethereum developers expected from the new upgrade.

    Ethereum Merge occurred on September 6 at epoch 144896 on the Beacon Chain, as planned. The Proof of work converted into Proof of stake.

    It's crucial to understand the Bellatrix upgrade's position in the larger road map leading up to the Merge before going into its details.

    This development is significant for the history of Ethereum and possibly for the entire sector. It will fundamentally alter issuance and operating details and is the first-ever switchover of a large-scale network from a Proof-of-Work (PoW) consensus to a Proof-of-Stake (PoS) consensus.

    Even though the Merge has already taken place, it was the outcome of years of study, creation, and testing. Additionally, it occurs after a number of improvements that ready the Ethereum network for it; here is where Bellatrix enters the picture.

    What is Bellatrix Upgrade and How It Works?

    The version of the Ethereum Virtual Machine that hosts the decentralised applications is called Bellatrix. Before integrating with the mainnet later in September, Bellatrix was the very final update that Ethereum's Beacon Chain would receive.

    Each Ethereum node is now represented on two different layers: the consensus layer and the proof-of-work layer, which together make up the current primary network (C layer). These two levels will be integrated as a result of The Merge as we move toward a PoS-based system.

    Through an application programming interface (API) engine, these layers talk to one another. To enable validators to begin creating updated Beacon Blocks, which will later contain the codebase for the merging of the two layers, the Bellatrix upgrade is necessary.

    According to the Ethereum Foundation, the update will increase the network's scalability, performance, and security. The installation of the Ethereum 2.0 Network is being paved over by it. The entire ecosystem will thus be more ready for widespread adoption. 

    The Serenity upgrade, the first stage of the ETH 2.0 update, will be made possible by the update, which will also prepare the way for it. The Casper consensus protocol update and then a Proof-of-Stake mechanism will be made available as part of the Serenity upgrade's second phase.

    The upgrade was cherished by Ethereum Founder Vitalik Buterin. He shared his Joy of emotions after the Hard fork upgrade took place.

    After the Upgrade

    The Merge is slated to happen in the so-called "Paris" update after Bellatrix. It is a part of the transition that affects the execution layer and will be started by a Terminal Total Difficulty (TTD) of 58750000000000000000000. The anticipated dates for this are September 13–15.

    A validator on the beacon chain will create the next block after the execution layer approaches or surpasses this TTD.

    As soon as the Beacon Chain completes this particular block, the Merge will be deemed complete. This will occur roughly 13 minutes (or 2 epochs) after the first post-TTD block is generated, assuming nothing unusual happens.


    The network is used by millions of people and has been helpful for many different businesses, but the protocol has had trouble expanding.

    The ETH 2.0 version is expected to address issues with scalability, speed up transactions, and introduce a new technique for code updates.

    Additionally, it will result in a more open governance structure, reinforcing and boosting the appeal of the Ethereum network.