Abstract: This paper is essentially a textual version of the Robert Farrell Memorial Lecture, delivered by Aidan O’Sullivan, on Thursday, May 12, 2016, for the American Society for Irish Medieval Studies. The lecture was based on the co-authors’ collaborative research project, entitled “The Early Medieval and Viking Houses Project,” at UCD Centre for Experimental Archaeology, which was funded by UCD Research Seed Funding Scheme. To recognize the discursive approach taken in the lecture, only further readings are suggested below, which provide access to the some of the archaeological and historical details.