The boundaries and status of North Wales are undefined (compared to regions of England), definitions and the boundary of North Wales with South or Mid Wales differs between organisations. It is strongly used culturally for comparison to the more urban South Wales. The most common definition for statistical and administrative purposes of North Wales contains the 6 principal areas of: Isle of Anglesey, Conwy, Denbighshire, Flintshire, Gwynedd, and Wrexham. Of which have a combined estimated population in 2018 of 698,400 people. Other definitions, especially historical, commonly include Montgomeryshire, one of the historic counties of Wales, to be part of North Wales. The definitions of North and Mid Wales constantly overlap, with Meirionnydd (southern part of the modern principal area of Gwynedd) sometimes considered Mid Wales.