Based on an IEEE definition and its adaptation by The Open Group enterprise architecture (EA) is often defined as the funda-mental organization of a company or government agency and the principles governing its design and evolution [16, 25]. While design representation issues like meta-modeling or notations have been discussed in EA literature [3], design activity issues and design principles in particular are often neglected. This is surpris-ing because EA principles play an important role in practice. As a contribution towards a clear definition of EA principles, we ana-lyze state-of-the-art EA principle definitions first. Based on this state-of-the-art analysis already discussed in [11] the original contribution of this paper is the construction and evaluation of a meta-model defining EA design principle as a second step. Our proposal differentiates a core definition of EA principle dealing with a principle itself (statement, rationale, implications, key actions, and measures) and an extended definition taking the use and impact of an EA principle in its environment into account. Important elements of an EA principle‘s environment are corpo-rate strategy, the constructional view on EA transformation projects, and EA itself including its layers and its dimensions in time like as-is and to-be EA. We evaluate our meta-model in two case studies. Our consolidated meta-model provides the basis to analyze phenomena of actual EA principles in practice and thus to uncover the latent structures of EA principle taxonomies.