John Langdon in Mills in the Mediaeval Economy (Oxford University Press 2004) refers to a mill at Erbury, Middlesex, in 1295. It was leased out and Dr Langdon describes it as having low investment rates. The type of the mill does not appear to be known, nor have I succeeded in establishing the exact location of Erbury.
In “Mill Drawings by Stephen Buckland”, Mills Archive 2014, on p.17 is an drawing (an enlargement) by Stephen based on an illustration of a windmill, looking very like a Dutch polder mill, and mounted on a square building which appears in the GLC reproduction of C J Visscher’s 1616 London panorama. Was this mill on the north bank (and therefore in Middlesex) or the south?