  Blockchain systems run consensus rules as code to agree on the state of the
distributed ledger and secure the network. Changing these rules can be risky
and challenging. In addition, it can often be controversial and take much
effort to make all the necessary participants agree to adopt a change.
Arguably, Bitcoin has seen centralisation tendencies in pools and in
development. However, how these tendencies influence blockchain governance has
received minimal community and academic attention. Our study analyses the
governmental structures in a blockchain by looking into the history of Bitcoin.
We investigate the process of changing consensus rules through a grounded
theory analysis comprising quantitative and qualitative data from 34 consensus
forks in Bitcoin and Bitcoin Cash. The results reveal the decentralised
behaviour in Bitcoin and blockchain. Our results are in contrast to related
work, emphasising centralisation among miners and developers. Furthermore, our
results show how the consensus-driven deployment techniques and governance of
consensus rules are intertwined.
