Month: April 2019

Baffling Bolingbroke: understanding Henry IV’s home

In rural Lincolnshire, nearly 30 miles east of Lincoln, stand the remains of a castle once held by royalty. The remaining walls and towers of Bolingbroke Castle are still 3m tall in some parts, and you can make out its distinctive hexagonal shape. The buildings that once crowded together inside the castle have long-since disappeared.

Bolingbroke Castle was founded in the 1220s by Ranulf de Blundeville, Earl of Chester and Lincoln and through marriage it ended up in the ownership of the House of Lancaster. John of Gaunt, Duke of Lancaster, lived here in the 1360s and the castle gave its name to his son Henry Bolingbroke, later crowned King Henry IV, who was born here in 1367. The history of the site is reasonably well documented, especially compared to castles not owned by the Crown, but there remain unanswered questions about its origins and development.

In 2018 we gave Heritage Lincolnshire a grant to delve deeper. They would carry out a geophysical survey to establish if there are buried remains immediately south of the castle and on Dewy Hill, which might be the site of an earlier castle, built before the stone one still visible at Bolingbroke.

Aerial photo of a green field surrounded by houses. At one end of the field stand the remains of a hexagonal castle.
Bolingbroke Castle on the left and the rectangular ‘Rout Yard’ on the right. Courtesy of Heritage Lincolnshire.

The plan was to use ‘magnetometry’. It works by measuring how magnetic the soil is and then plotting the results on a map. It allows you cover a large area quickly, and over the course of two days the Heritage Lincolnshire team surveyed more than five hectares (about five times the size of Trafalgar Square).

There is some natural variation in the soil, but typically human activity such as cooking hearths or stone walls have a different magnetic signature to the soil around them as they are made from different materials. Magnetometry can also be used to find filled-in ditches as the fill might contain traces of human occupation.

The first stage was to survey Dewy Hill, sitting 400m north-west of Bolingbroke Castle. It was excavated in the 1960s, and a digital survey of the terrain suggests a rectangular feature still survives. We hoped the geophysical survey would show how extensive the buried remains are, and the shape and size might give us an idea of what it is. Essentially, was it a castle or some other type of important place? There was a slight hitch…

But Heritage Lincolnshire did eventually get to take their magnetic gradiometer for a spin! Next, they surveyed the area south of the castle as it might contain an extension of the castle which has since been dismantled. Are there traces of this possible enclosure, or was there perhaps a garden here? In the later Middle Ages it was especially popular to shape the landscape around a castle. Right in the middle of this area is a rectangular piece of ground called the ‘Rout Yard’, but it’s unclear when it was created so the survey aimed to establish how this area relates to the castle.

Understanding the results takes a trained eye, and Heritage Lincolnshire have a highly skilled team of experts. They were able to find a few anomalies, but they either appear to be modern (there may be a concrete slab on Dewy Hill) or natural geological features.

The point of an exploratory project is to find out what lies beneath. Oddly, we expected something to be at Dewy Hill since earlier excavations suggested there might be some activity. The search for a possible bailey suggests that perhaps one did not exist or if it did it may have been insubstantial. That would mean the ruins we see today may represent the extent of the castle at its peak. Interestingly the fashion for having gardens might have passed Bolingbroke by. It was an important place, so may have begun to fall out of use by the time gardens became a common part of high-status medieval landscapes.

Despite the siege of 1643, the survey did not uncover ‘siegeworks’ which would have been built by the Parliamentarians. This might be because the siege was relatively short.

As a result of this work, we know more about how the surroundings of Bolingbroke Castle. Other types of geophysical survey may pick up different pieces of evidence, helping build a fuller picture of the area. Surveys like this are an important tool to understand sites, and Heritage Lincolnshire’s work will inform any future work at the castle.

Thank you to the owners, the Duchy of Lancaster, for allowing us to carry out the survey, to English Heritage who are guardians of the site, and to the volunteers from the local community who helped with the fieldwork. Projects like this really do take a village.

A full report has been prepared by Heritage Lincolnshire.

Wild Fire or Greek Fire? Game of Thrones and medieval sieges

It is a fact that millions more people have gained a view of medieval sieges by watching Game of Thrones than by reading books by experts or learning history at school, so it is worth asking: how true a picture does the blockbuster series give?

Across the seven series so far, we have seen many bloody captures of strongly fortified cities and castles by large armies of armoured warriors, supported by archers and fleets of ships. The attack on King’s Landing (series 2, ep. 9) provided some realistic glimpses: the preparations of the citizens and garrison for battle, the taking refuge in the keep of women and children – and the exemplary execution of attendants who tried to flee. The ominous clanging of the bells gave warning of assault heralded by banging drums and the landing and drawing up of the attacking army, the bringing up of a large battering ram to batter down the main gate while scaling ladders were prepared. As everyone knows, the city was saved when the dwarf prince Tyrion inspired his men by appealing to their commitment to their families and homes to launch a sally via a postern gate which took the besiegers in the flank, and, accompanied by the timely arrival of a relieving army, saved King’s Landing.  Prior to this, the invading fleet had been consumed by the launch of the lethal ‘wildfire’ via a fireship.

Bronn lighting the wildfire with a flaming arrow. Image ©HBO.

Was ‘wild fire’ inspired by the famous ‘Greek Fire’? The real ignis graecus (mentioned in numerous Latin chronicles) was invented by Byzantine engineer Kallinikos and used to save Constantinople from Arab attack in 672 AD: its exact constituents remain unknown to this day but like ‘wild fire’, it could not be extinguished by water (hence its main use at close range against enemy ships), and among its secrets was the means of propulsion – possibly by siphon mounted on the front of ships, or on castle towers. The original formula was lost but incendiary devices continued in use, especially during the crusader period, using plentiful supplies of oil. But never again were they so decisive.

Other regular features of medieval sieges appear in GoT. The threat of hanging hostages in view of the occupants if they did not surrender, shown in the siege of Riverrun (ser. 6, ep. 7–8), maybe echoed the threat of King Stephen to kill the child who became the ‘greatest knight’, William the Marshal, if his father did not surrender Newbury (1152): in both cases the putative victims were reprieved. In other respects too a realistic scenario is painted: the besiegers erecting defences to protect their rear, building siege towers and stone throwing trebuchets, and setting camp in a vast array of pavilions flying numerous banners; defenders gathering sheaves of arrows and relying heavily on crossbows which, used from behind stone walls, could be devastating.

The siege of Riverrun. Image ©HBO.

Riverrun yielded. At other times, the attackers avoided the risk of an assault by exploiting tunnels to enter – Tyrion and Daenerys captured Castly Rock (ser. 7, ep.3) through the sewers. In 1204, King Philip Augustus’ army stormed the middle bailey of Richard the Lionheart’s ‘impregnable’ Château Gaillard in Normandy when one of his men discovered a drain outlet in the ditch that led him up into the chapel.

GoT skates over many realities of medieval warfare, particularly questions of logistics. The siege weapons materialise from nowhere when in reality they needed time for construction. All are settled quickly, whereas most medieval sieges lasted a long time, and hunger and disease killed far more people than fighting. However, many episodes convey brilliantly the drama, the sheer terror, and the brutal horror of combat. So we should recognise GoT as brilliant drama rather than history, and look elsewhere for accounts of real medieval warfare. But while we’re about it, we can only imagine what a medieval general would have given for the three fire-breathing dragons Queen Daenerys unleashed at Meereen (ser. 7, ep. 9).

Dr Peter Purton (author of History of the Early Medieval Siege and History of the Late Medieval Siege (Boydell Press 2010).