  In September 2022, Ethereum transitioned from Proof-of-Work (PoW) to
Proof-of-Stake (PoS) during "the merge" - making it the largest PoS
cryptocurrency in terms of market capitalization. With this work, we present a
comprehensive measurement study of the current state of the Ethereum PoS
consensus layer on the beacon chain. We perform a longitudinal study of the
history of the beacon chain. Our work finds that all dips in network
participation are caused by network upgrades, issues with major consensus
clients, or issues with service operators controlling a large number of
validators. Further, our longitudinal staking power decentralization analysis
reveals that Ethereum PoS fairs similarly to its PoW counterpart in terms of
decentralization and exhibits the immense impact of (liquid) staking services
on staking power decentralization. Finally, we highlight the heightened
security concerns in Ethereum PoS caused by high degrees of centralization.
