LINCOLNSHIRE before the Romans was occupied by the Corieltauvi a British tribe. There have been several small pre-Roman barrows discovered near to Boston and Frampton.

The Romans established permanent government in Lincolnshire soon after the invasion of AD 43, but the tyrannical rule of the Roman sub-prætor Ostorius Scapula so inflamed the Corieltauvi and their neighbours in Yorkshire, the Brigantes, that they conducted a simmering low key rebellion lasting well into AD 70.

Eventually, the Governorship of Britain was given to the Deputy of the Prefect of Gaul and the title Vicar of Britain created. He resided at York, and the sub-district of Flavia Caesariensis, which comprised Lincolnshire and parts of the Midlands was created.

Once established, the Romans set about improving Lincolnshire. They created the Car Dyke, a series of semi-natural and artificial boundary ditches which run from the River Welland at Market Deeping for 64 km to the River Witham at Washingborough, constructed hard standings and walkways across the fens, and also built inland ports such as the Brayford Pool at Lincoln.

The main Roman forts in Lincolnshire were:

  • Ancaster
  • Brant Broughton (Briga)
  • Caistor
  • Broughton (Praetorium)
  • Horncastle
  • Kirton in Lindsey (Inmedio)
  • Lincoln (Lindum Colonia)
  • Louth (Luda)
  • Ludford
  • Stow (Sidnacester)
  • Tattershall (Drurobrivis)
  • Torksey (Tiovulfingacester)
  • Wainfleet (Vainona)
  • Willoughby (Verometum)
  • Winteringham (Ad Abum)

The Romans built three main roads through Lincolnshire:

  • Ermine Street (London to York via Stamford, Lincoln and Winteringham)
  • Fosse Way (Lincoln to Exeter)
  • Tillbridge Lane (Lincoln to York via Marton and Littleborough)

Other roads of Roman origin are the Salters' Way, continuing the line from the Leicestershire border across Ermine Street near Old Somerby, to the then coast at Donington. King Street including The Long Hollow road, joined Ancaster to the fen edge and Durobrivae near Peterborough. Two roads linked Lincoln to the coast across the Wolds. This was used as part of the defence system set up to protect the Saxon Shore and re-used by William the Conqueror in conjunction with Lincoln Castle. There are also scores of smaller sections of roads branching off from the three major routes which are certainly Roman as well, linking Ermine Street with the Wolds and King Street with the coast. Also, Mareham Lane continued the fen-edge line of King Street northwards.

When the Romans departed in the fifth century, all these works gradually fell into ruin and disrepair.

Incoming groups of Angles settled heavily in the Midland and East Midland areas of what is now England. The Anglian Kingdom of Lindsey was established between the Witham and the Humber, in the northern part of the what is now Lincolnshire, by the 6th century and seems to have maintained its independence until at least the end of the 7th century, but was absorbed into Mercia - a rising power - in the 8th century.

In 865 a formidable Danish raiding army, led by Ivar (spelled Hinguar or Igwar in English sources), one of the sons of Ragnar Lothbrok, landed in East Anglia and established winter quarters there. Within a few years this force succeeded in conquering Mercia and all the other Anglo-Saxon kingdoms except Wessex.

Scandinavian settlers followed the raiders into the swathe of England under Danish control, which became the Danelaw. They have left a legacy of Scandinavian elements in many Lincolnshire place-names. Lincoln became a Danish borough. In the 10th century it became the head of the new shire of Lincolnshire.

The Anglo-Saxon nobility of Lincolnshire was destroyed by William the Conqueror, and the lands divided amongst his followers. He constructed Lincoln Castle, and another at Tattershall. Numerous others were built by Norman magnates, mainly in the years immediately following the Conquest and around 1140, during the period of civil war when Stephen and Matilda were disputing the right to rule. The First Battle of Lincoln, in 1141, was part of this.

The Witham valley between Boston and Lincoln had the highest concentration of Abbeys and monastic foundations in the country. The principle foundations were Barlings Abbey, Bardney Abbey, Catley Abbey, Nocton Abbey, Stainfield Abbey, Stixwould Abbey, Tupholme Abbey, Kirkstead Abbey, Kyme Abbey . The rest of the county was not left out, there were houses at Bourne Abbey, Sempringhm Abbey and many other places. But the clustering along the Witham was extraordinary.

Fewer Castles were built, although some of the manors were fortified in early years. Given the size of the county it is perhaps just as surprising that there are so few castles, as that there are so many Abbeys up the Witham. Boston, for example, appears to have had seven friaries, and to be defended only by the town walls. There appears to have been no garrison.

Fairs at Stamford, Grantham, and Stow Fair were established, and lasted throughout the period. Corby Glen sheep fair has been held more or less unchanged every year since 1238.

Sheep farming and the wool trade brought untold wealth to the area. Churches of breathtaking beauty were built.

In this period the Queen's Champion was appointed, and the post is still held by his successor, and many great estates and schools were founded. The Middle Ages were as rich and colourful in Lincolnshire as anywhere else. Events like the accusations against the Jews or the Lincolnshire rebellion show that life was not all a sybaritic idyll.

An important medieval book, the Luttrell Psalter forms the basis for nearly every schoolbook illustration of the period. It lay unregarded in the church at Irnham until the early 20th century when it was saved for the nation: a public subscription in a popular newspaper raised enough to buy it before it was sold overseas.

Grantham's St Wulfram's church has a fine example of a Chained library still extant within the church.

During the war, Lincolnshire was part of the Eastern Association, the Parliamentarian alliance. On its western border lay the Royalist strongholds, of Newark on Trent and Belvoir Castle. Lincolnshire was therefore raided and defended by the respective parties. For a time, Crowland, in the south of the county was fortified for the king.

Lincolnshire was important to the Parliamentarians as it provided access between the great arsenal of Hull and the south and the Eastern Association's heartland in the east of England. It also offered a potential starting line for an advance across the English Midlands, cutting the north of England off from the west.