The paper reviews important concepts in the studies and conceptualization of varieties of English across the globe. The philosophical backgrounds underpinning these varieties of English are put forward, showing the arguments surrounding the modelling of varieties of English across the board. Kachru’s three circle model which has clearly been cited and revised in the literature is discussed, showing its contribution and importance to the categorization of varieties of English in three different developmental stages. A commonly understudied model, a Map of World English is brought to the fore front, showing how the common shortcomings of Kachru’s Three Circle Model have already been accounted for in the literature. The other main contribution in this paper is the proposal of a model accounting for the evolution of outer circle varieties of English from the perspective of Nigerian variety of English. In other words, the historical events involving the evolution of Nigerian variety of English is clearly permissible for such similar outer varieties such as Ghanaian, Singaporean, Indian English, except for idiosyncratic socio-political events that are less relevant for the development of the language all the years long.