The Nuttall Encyclopedia
That part of Ireland in which after the invasion of 1172 the supremacy of English rule and law was acknowledged, the limits of which differed at different times, but which generally included all the eastern counties extending 40 or 50 m. inland.
Wood, James, ed. Entry for 'Pale, the'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/p/pale-the.html. Frederick Warne & Co Ltd. London. 1900.