The history of English land law can be traced for eons, into Roman times, and through the Early Middle Ages under post-Roman chieftains and Saxon monarchs where, as for most of human history, land was the dominant source of personal wealth. English land law transformed further from the Saxon days, to post-Norman Invasion feudal encastellation, from the Industrial Revolution and over the 19th century, as the political power of the landed aristocracy diminished, and modern legislation increasingly made land a social form of wealth, subject to extensive social regulation, such as for housing, national parks, and agriculture.