After William’s conquest of England following the invasion of 1066 the Norman barons were rewarded with vast tracts of land. Thirsk and its surrounding region formed part of the estates of the powerful Mowbray family and the building of a castle on this site was probably carried out around 1092 by Robert de Mowbray who was then Governor of Northern England. It was from Thirsk that Robert de Mowbray marched north to defeat an army of invading Scots led by their King Malcolm who was cornered and slain at Alnwick.
By the time of King Stephen (1135-1153) Thirsk Castle was the home of the young Roger de Mowbray and his widowed mother lady Gundrea de Albini. In 1138 a group of twelve monks led by Abbot Gerold arrived in Thirsk. Four years earlier they had been sent from their Savigniac monastery at Furness to found a new abbey at Calder in Cumberland, but fleeing from marauding Scots, they had come to Yorkshire to find a place to establish themselves. Gundrea sheltered them here in Thirsk before sending them on to settle at Hood on the edge of the Hambleton Hills where her uncle lived the solitary life of a hermit. It was these monks who, after several abortive attempts at establishing a permanent monastery, exchanged their Savigniac rule for the Cistercian mode and, with substantial grants of land, founded Byland Abbey in 1177.
In 1138, the year the monks came to Thirsk, there was renewed fighting with the Scots who had swept through Northumberland and Durham and across the Tees. They were opposed by the Yorkshire barons led by Thurstan, Archbishop of York. To encourage the English army, the Archbishop contrived a great mast mounted on wheels, topped by a casket holding a consecrated wafer and flying the banners of the four patron saints of the North; it was to be the rallying standard in the fight that was to follow. Mustering at Thirsk, the barons marched to meet the Scots just beyond Northallerton, where the English army routed the Scots in the Battle of the Standard and drove them back beyond the Tees.
In the years that followed, Roger de Mowbray joined the party of Prince Henry in rebellion against Henry II. Roger had backed the losing side, however, and though pardoned by the King, his castles were declared forfeit and destroyed in 1176.
Thirsk Castle was an example of a motte and bailey construction. This was a style brought to England by the Normans and was the simplest type of mediaeval castle. The motte was a conical mound of earth or rubble on which stood a timber tower. This stronghold could be surrounded with a ditch and a palisade. Around this stretched a level open space, the bailey, enclosed by a rampart formed by earth thrown up from a ditch on the outside; the rampart was in turn topped by a stout palisade.
Castles like this were built in the early stages of the Norman Conquest as garrison forts in strategic positions; over six hundred examples have been recorded. Many later became aristocratic residences and administrative centres, the more permanent being rebuilt in stone. Thirsk Castle never developed beyond its initial stage and was demolished before the end of the 12th century. Nothing of the fabric of the castle is visible, but the late-Victorian Castle Villa stands in a prominent position on the remains of the motte. The western limit of the bailey is still marked by the impressive rampart which lies in front of you and the ditch where you are now standing. Over the centuries, and especially in more recent times, buildings have encroached upon the site. Castle Garth itself, however, has never been built on - it has served as garden or paddock down the years and is now adopted by Thirsk Town Council and preserved as an open space for the enjoyment of the community.
In the summer of 1994 an archaeological excavation took place on this part of the site in connection with the installation of a sub-station by Northern Electric. The dig revealed a hitherto undetected sixth-century burial site. This discovery confirmed the belief that Thirsk existed as a settlement long before the arrival of the Normans in the late 11th century.
When the Roman Legions were withdrawn from northern Britain in AD 402 there were already people from the north-western part of Europe settled here as part of the Roman army and as time went by they were joined by more immigrants from across the North Sea. The folk settling in Yorkshire were Angles rather than Saxons and by AD 560 an Anglian chieftain called Aella ruled over a north-eastern kingdom called Deira. The graves found here belong to the first half of the sixth century and the artifacts associated with them are in a typically Anglian style.
The archaeologists found that graves had been disturbed at a later date, probably when the castle ditch was dug, but had not been robbed. From the size of the bones found in one of the graves we know that the man buried there stood about seven feet - well over two metres - tall. Were there giants in those days?
Full details of the 1994 dig and the finds from the site can be found at Thirsk Museum in Kirkgate.