The research focuses on the relationship and interlinking between the different architectural domains within the enterprise architecture of an enterprise. The architectural domains are grouped together as business architecture, information architecture and technology architecture. First, a literature review of the definitions, history, role, functions and qualities, existing frameworks, models and domains of enterprise architecture was conducted. The definitions; role and benefits; models, frameworks, ontologies and descriptive languages of the different architectural domains were then studied as background and basis. New definitions were deduced. Second, the modelling methodology, process, elements and deliverables were investigated. An integration metamodel for enterprise architecture was developed, according to this modelling methodology. The metamodel is called the Relational Enterprise Architecture Metamodel or the REAM. Third, the research methodology for the empirical research section was investigated and determined. The proposed conceptual metamodel has been assessed through a case study within three different industries each. The feedback from the case studies was used to modify/enhance the metamodel. The possibilities for application of the modified model were then assessed at the University of Pretoria. The contribution of this research lies mainly in the development, empirical testing and refining of an integrated EA metamodel (REAM) as well as the development of new definitions for enterprise, business, information and technology architecture and relating them. / Thesis (PhD)--University of Pretoria 2015. / Information Science / Unrestricted