* Remigius appointed to Bishopric of Dorchester by William the Conqueror (‘reassigned’ bishopric of Lincoln in 1072) 1217
* Second Battle of Lincoln, or Battle of Lincoln Fair, was fought around Lincoln Castle between the forces of the future Louis VIII of France and Henry III (20 May)
* The Charter of the Forest, which re-established rights of access to the royal forests for free men, first issued (6 Nov). One copy is on display alongside Magna Carta at Lincoln Castle.
*Lincoln Endowed Grammar School founded
*King James I came to Lincoln for a visit of several days. He attended Cathedral services but also watched a cock-fight at a pub near the Stonebow and enjoyed a horse race (late March).
* First edition of the Lincoln, Rutland and Stamford Mercury (3 Jan)
* Sir John Thorold, MP for Grantham and Lincolnshire 1697-1715 died (14 January)
* Robert Vyner of Gautby, MP for Thirsk 1783-1796, born (27 June)
* John Harrison, clockmaker of Barrow on Humber, made a clock with entirely wooden mechanism for Nostell Priory, Wakefield, owned by the Winn family
* William Stukeley, antiquarian of Holbeach, elected Fellow of the Royal Society
* Maurice Johnson of Spalding assisted in the formation of the Society of Antiquaries
* Enclosure Awards granted for Grimoldby (9 December), Keddington (5 March), Tetford (2 April), Fenton & Laughterton , Aslackby & Dowsby (3 November) and Corby.
* Severe flooding in fens, breach in the Deeping Bank and north bank of River Glen (9 Feb)
* Earthquake recorded at Coningsby (6 Feb)
* Annie Dixon, miniaturist portrait painter to royalty and nobility, born Horncastle (13 March)
* William Marrat’s map of Lincoln, 10 inches to 1 mile, published with dedication to Coningsby Waldo Sibthorp
* Edward Trollope, antiquary, Anglican Bishop of Nottingham, born Uffington (15 April)
* Elizabeth Whiting, convicted of poisoning her child, first person to be hanged on Cobb Hall, Lincoln (15 March).
* Page Cartledge, introduced gas, made on the premises, for lighting his grocer’s shop in Lincoln (5 May)
* The original building of the Lawn Lunatic Asylum opened in Lincoln (25 August)
* William Rainforth, agricultural implement maker, Britannia Works, Lincoln, born Gainsborough
* Samuel Jessup, farmer of Heckington, died aged 64 (17 May). An extreme hypochondriac, he is reputed to have taken over 50,000 pills in one year and owed a local apothecary about £800 when he died.
* The Crowland to Eye Turnpike Trust formed, one of the last in Lincolnshire; the turnpike was only 5 miles long and lay mostly in Northamptonshire.
* A House of Industry (workhouse) was set up within the Newark Union at Claypole.
* The London Warehouse, a fine, substantial building, was erected on Packhouse Quay, Boston; it was demolished in 1950.
* Trustees savings banks opened in Boston, Horncastle and Louth.
* Harvest wet and cold, worst ever known.
* Railway lines were opened between Spalding and March (GNR March line, 1 April); Lincoln and Honington (GNR Honington line, 15 April); and Gainsborough and Doncaster (part of GNR Loop Line, 15 July)
* The airfield at Bracebridge Heath was extended to 125 acres for service use by larger planes and the Royal Flying Corps.
* Marshalls of Gainsborough received orders to build 150 Bristol F.2B aircraft; they were built at the Carr House Works, Lea Road.
* William Ashbee Tritton (1875-1946) received a knighthood for his part in the development of the tank at Fosters of Lincoln (21 Feb).
* Rowland Winn, The Second Baron St Oswald, became the largest single producer of iron ore in the UK at his Scunthorpe area mines.
* The Hon Francis McLaren, Liberal MP for Spalding (1910-1917), joined the RNVR and was killed in a flying accident in Scotland (20 August)
* The Grimsby Chums took part in the battle of Passchendaele (October)
* Holbeach Crown Colony was set up with help of the Ministry of Agriculture to provide farm smallholdings for discharged soldiers.
* Home Defence Flight Station Brattleby Cliff was renamed Scampton RFC Station, with operational training squadrons 11, 60 & 81 flying Sopwith Camels, Pups and Dolphins.
* The Cranwell Branch railway line from Sleaford, built by the Admiralty, under GNR supervision, opened with 5.25 miles of single track.
* The ironstone mines at Nettleton reached their peak level of production (but closed two years later).
* Stamford was designated the country’s first conservation area under the Civic Amenities Act 1967.
* Jimi Hendrix and Pink Floyd performed at Spalding’s Tulip Bulb Auction Hall before a crowd of 4000. Tickets were £1. (29 May)