This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The last two decades have seen rapid evolution of Information and Communication Technology (ICT) capabilities in the public sector which facilitate the adoption of several IT innovations. E-government is one of these strategic innovations that many government organisations have considered adopting to deliver government information and services to citizens and to support the modernisation of their business processes. This work therefore investigates this issue through a study of the impact of e-government on government organisations and their capabilities towards the e-government adoption. This has led to developing a framework for e-government adoption that outlines the implementation process, determines critical factors influencing adoption, and identifies barriers that could keep government organisations behind the advanced stages of the implementation process. The research also proposes a novel architecture framework for e-government that offers a clear picture of ICT requirements, along with a business process model needed for the implementation for e-government. This framework also supports the researcher in terms of validating the proposed conceptual framework in case organisations. The researcher, by adopting a qualitative case study strategy, examines the proposed framework in three government organisations in the Kingdom of Bahrain.. The analysis of empirical data comes up with a novel comprehensive framework for e-government adoption in the public sector that can be a benefit in multiple ways. The major benefit of this framework is to reduce the confusion surrounding e-government adoption in the public sector by understanding the implementation process, identifying the requirements of ICT tools, and highlighting the importance of organisational readiness and the impact of the environment. The framework can also help decision makers in government to provide a clear strategic action plan for e-government. Finally, the proposed framework can be used by IT experts to estimate the progress level of their e-government projects