Goal oriented modelling (GOM) is one of the most prominent and widely accepted techniques in information systems research. Since the early 1990’s, a large number of GOM approaches have been proposed aiming to a better alignment between business strategy and the behaviour of supporting systems. Different GOM approaches focus on different activities in the early stages of system development and propose a variety of strategies for reasoning about goals. A number of researchers have stressed the advantages of integrating different GOM techniques, especially in the context of modern global business environments. This is evidenced in the increasing number of publications in this area. However as each GOM language (even versions of the same language) comes with its own syntactic and semantic singularities, such integration requires a number of complicated transformations which is a major obstacle to model and tool interoperability, and prevent wider adoption by practitioners. In order to provide a unified view of GOM, one needs a common understanding of GOM concepts, their semantics and deployment. To this end, this paper proposes a language independent meta-model based on the analysis of eight GOM languages. Generic concepts were identified and a robust semantic definition among these concepts was built in a unified meta-model. We claim that the unified GOM meta-model could help in a) analysing existing goal models in order to provide insights regarding different goal modelling perspectives b) identify semantic similarities / overlaps between existing GOM techniques c) provide the basis for a reference model for GOM.