There is an anonymous letter to Elizabeth I (The Epystle to the Queen’s Majestie) in the National Archives which contains a proposal to reinstate a fortified line (the ‘Loyall Worke’) between England and Scotland. It has been suggested that this letter was written by Christopher Dacre, who not only lived at Lanercost and was thus familiar with the Wall at close quarters, but had also served on a commission to review the state of contemporary frontier fortifications, during which he drew up a scheme for a ‘Dyke’ to run from the Tweed to Bowness. The Epystle is likewise not simply a plan to rebuild the Roman Wall, but rather an adaptation of the concept of a mural barrier which incorporated the latest Italianate style of fortification in the form of sconces, a beefed-up cross between a milecastle and a fort. Like all brilliant ideas by slightly crazed military geniuses (one need only think of the equally anonymous Late Roman treatise De Rebus Bellicis, which was packed with wacky ways to save the Roman Empire, or some of the bizarre machinery trialled during the Second World War) it was doomed to failure. This cunning plan appears to be tinged with bitterness, for although his original scheme was taken seriously, it was dropped, so the Epystle may be his response to that rebuff, addressed directly to the Queen.
Even today, governments build walls to solve (or, perhaps more accurately, kick into touch) problems they wish would go away.
Further reading: Merriman 1984