start of the 14th centuries, twenty-five to thirty years after the bridge itself was built. The siting of the gatehouse mid-channel is relatively unusual; the archaeologist David Harrison notes the more common arrangement was for the gate to be situated on the roadway at one end of the bridge. In 1297, Edward I provided a murage grant in favour of Monmouth in response to a request from his nephew, Henry of Lancaster. A murage was a medieval tax, granted specifically to allow for the raising of funds to construct or repair town walls. The grant allowed the townspeople to build the town walls and gates, including the construction of the gatehouse. By 1315, work was incomplete or required repair, as the original authority was renewed on 1 June of that year. At that time, the bridge would have been much narrower than now, with all traffic passing beneath a single arch. The arch was protected by a portcullis, whose associated grooves are still visible. The prominent arched machicolations, defensive apertures through which stones or other material could be dropped on attackers, were added at an unknown date in the medieval period, possibly in the late 14th century. The gate formed part of the town's defensive walls. The cartographer John Speed's map of 1610 shows walls only on the northern side of the town, which lies unprotected by either the Monnow or the Wye, but the archaeologist Ian Soulsby suggests it is "inconceivable" that Monnow Gate, and another gate shown by Speed leading out onto Chippenham Mead, stood alone. As well as its defensive role, the gatehouse served as a barrier to allow for the collection of tolls from those attending markets. Tolls were authorised in the Patent Rolls of 1297 and 1315 and in subsequent town charters. Kissack gives details of the wide variety of items on which tariffs were levied in his reproduction of the charter of 1297. These included "five fat hogs, (a) horse-load of honey and a thousand (roofing) nails". In 1447 Henry VI granted the town a Charter of Incorporation which enabled further development. Historians have debated whether defence or revenue collection was the gatehouse's primary purpose. The Victorian antiquarian Mary Ellen Bagnall-Oakeley, who wrote the first history of the bridge and gate in 1902, described the gatehouse as "a little fortress complete in itself, though of course, useless in time of war". Her account contended