A line in the Domesday Book reads: "Lincoln was, York is and London will be." Lincoln was once an exceptionally important city of the Romano-British empire.
Originally a base for Roman legions, until they pushed further northward, it became a settlement for retired legionnaires and their families, receiving the name "Lindum Colonia" for its troubles. The town then spread around the legionary camp along the northern edge of a valley, with the then very important (and, more importantly, navigable) River Witham flowing across the bottom.
To ensure stability and a strong fortification, the wooden fences surrounding the camp were replaced with stone walls, some of which are still visible today around the Newport area of uphill Lincoln, included in which is an arch, allegedly the only Roman arch in England which still has traffic flowing under it.
With the Roman love of roads, Lincoln has Ermine Street running up from the south and continuing north as a fine example of this, almost perfectly straight (except for just north of Lincoln, where the RAF during WWII had to change the direction of the road into a half-moon shape to lengthen the runway at the RAF base at Scampton to allow the Lancasters, of the Dambusters fame, to take off!!).
Once the Romans had deserted Pax Britannia, there appears to have remained behind a settlement behind the stone walls right up to the Viking invasions of the eighth and ninth centuries, when it appears to have flourished somewhat with the assistance of Danish trade and coinage. The first example a church built in the cathedral area is recorded around this time, and also for the first time, people are moving from uphill Lincoln into the valley itself.
Many Saxon and Danish village names are prevalent in the Lincoln area (villages with the "-ton" or "-ham" ending are Saxon, and any with the "-by", "-ley" or "thorpe" are Viking), Lincolnshire being very heavily part of the Danelaw, the area of the country agreed by King Alfred to remain under Danish control.
After defeating Harold at Hastings, the Normans paid Lincoln a visit, building a fine castle on the site of the original Roman garrison. Much of the castle still remains today, but it is dwarfed by its angelic neighbour. By this time, Lincoln was still the third most important city in the realm, much of the prosperity being built upon the wool for which Lincoln was famous throughout Europe.
In the 13th century, work was started on the cathedral, at a site next to the castle. This work would not be finished for another 220 years.
The 14th to 18th centuries saw Lincoln in dramatic decline, with a failure of the cloth market, the plague, the English Civil War (Lincoln sat on the fence, stuck between Royalist Newark and Parliamentarian Hull, but this helped no one).
Slowly from the mid-18th century, Lincoln slowly recovered, though never reaching its former prosperity. From 1801 to 1851, the population more than doubled; in 1846, the first railway station in Lincoln was opened, and courthouses and prisons, as well as theatres and hospitals, were built.
Lincoln continued to grow, although on a much smaller scale, throughout the 19th and 20th centuries. It is now home to over 80,000 hearty souls, spread across much of the valley floor, the uphill area around the castle and cathedral now being areas of prime real estate and centres of great historic interest.