Aberdeen Docks Achill Sound Afon (River) Mawddach Afon (River) Seiont Afon (River) Soch Afon (River) Taff Afon (River) Tawe Afon (River) Teifi Afon Nedd (River Neath) Afon Tywi (River Towy) Afon Wysg (River Usk) Aire & Calder Navigation Ardrossan Harbour Ashby Canal Ashton Canal Avonmouth Docks Barnsley Dearne and Dove Canals Barrow Navigation - Ireland Barrow-in-Furness Docks Barry Docks Basingstoke Canal Benfleet Creek Birkenhead Docks Birmingham and Fazeley Canal Birmingham Canal Navigations Birmingham Canal Navigations - Titford Canal Black Cart Water Bowcombe Creek Bradford Canal Bridgewater Canal- Manchester Bridgwater and Taunton Canal Bridgwater Docks Brighton Marina Bristol Harbour Buckingham Arm Bude Canal Burntisland Docks Burry Port Burwell Lode Caldon Canal Caledonian Canal Cambridge Arm Cardiff Bay Cardiff Docks Carlisle Canal Castletown Harbour Cattewater Chatham Docks Chelmer and Blackwater Navigation Chichester Canal Coventry Canal Crinan Canal Cromford Canal Cromford Canal - Pinxton Branch Croydon Canal Deptford Creek Derby Canal Devonport Dockyard Douglas Harbour Dover Docks and Marina Driffield Navigation Droitwich Barge Canal Dudley Canal Dundee Harbour Dutch River Eglinton Canal Erewash Canal Exeter Canal Exmouth Quay Eye Water Faversham Creek Folkestone Harbour Forth and Clyde Canal Fosdyke and South Witham Navigation Glamorganshire Canal Gloucester and Sharpness Canal Gloucester Docks Goole Docks Gosport- Forton Lake Grand Canal- Ireland - Mountmellick Canal Grand Surrey Canal Grand Surrey Canal Grand Union Canal Grand Western Canal Grangemouth Docks Grantham Canal Greasbrough Canal Great Northern Railway Great Ouse Greenock Docks Grimsby Docks Grosvenor Canal Hartlepool Docks Hatherton Canal Havengore Creek Hedon Haven Hereford and Gloucester Canal Hooe Lake Huddersfield Broad Canal Huddersfield Narrow Canal Hull Docks Ipswich and Stowmarket Navigation Kennet and Avon Canal Kings Lynn Docks Lancaster Canal Langstone Harbour Lartigue Monorail Leeds and Liverpool Canal Leigh Branch Leith Docks Leven Canal Lichfield Canal Lichfield Canal Little Ouse,RIver Liverpool Docks Llangollen Canal London & South Western Railway London Docklands - Tilbury Docks London Docks - East India Docks Lossiemouth Docks Louth Canal Lowestoft Harbour and Lake Lothing Lydney Harbour Macclesfield Canal Manchester & Salford Canal Manchester Ship Canal Market Weighton Canal Maryport Docks - Cumbria Mersey and Irwell Navigation Middlesbrough Docks Milford Haven Monmouth and Brecon Canal Montgomery Canal Naas Harbour Neath & Tenant & Swansea Canal New Junction Canal Newport Docks Newry Docks Nottingham Canal Oxford Canal Peak Forest Canal Peel Harbour Penarth Docks Penzance Harbour Peterhead Docks Plymouth Dockyards Pocklington Canal Poole Harbour Portsmouth and Arundel Navigation Portsmouth Harbour Portsmouth Royal Dockyard Ramsey Harbour Ramsgate Docks Regent's Canal River Adur River Ancholme River Ant River Arun River Avon - Bristol River Avon - Warwickshire Avon River Bann River Blackwater River Blyth River Bure River Chess River Clyde River Colne River Darent River Dee River Derwent - Derbyshire River Derwent - Yorkshire River Don River Douglas River Ellen River Esk River Exe River Forth River Foss River Hamble River Hayle River Hull River Irvine River Irwell River Kent - Cumbria River Lee - Ireland River Leven - Cumbria River Liffey River Medina River Medlock River Medway River Mersey River Mole River Nene River Orwell River Ouse - Yorkshire River Ouse - Sussex River Parrett River Ribble River Roach River Roding River Rother River Severn River Shannon River Slaney River Slea River Soar River South Esk River Stort River Stour - Kent River Suir River Suir River Taw River Tees River Teign River Thames River Thurne River Trent River Trent Navigation River Tyne River Waveney River Welland River Wensum River Yar River Yare River Yeo Rochdale Canal Rosyth Docks Rothesay Harbour Royal Arsenal Canal Royal Canal - Ireland Rushall Canal Salford Quays Saltholme Nature Reserve Moat Sandwich Port and Haven Sankey (St. Helen's) Canal Scarborough Harbour Selby Canal Sheffield and South Yorkshire Navigation Shrewsbury and Newport Canal Silver Burn Somerset Coal Canal Southampton docks Sovereign Marina - Eastbourne St. Andrews Harbour St. Mawes Castle Staffordshire and Worcester Canal Stainforth and Keadby Canal Stratford-upon-Avon Canal Stroudwater Canal Sunderland Docks Surrey Commercial Docks Swale, The Swansea Canal Swansea Docks Tavistock Canal Thames and Medway Canal Thames and Severn Canal The Challenge Torquay Harbour Tralee Ship Canal Trent and Mersey Canal Ulverston Canal Union Canal - Scotland Wallesey Pool - none Walney Channel Water of Leith Weaver Navigation Weston Canal and Docks Wey and Arun Canal Weymouth Docks Whitby Harbour White Cart Water Whitehaven Docks Wilts and Berks Canal Worcester and Birmingham Canal Wyrley and Essington Canal   

The Grand Junction Canal (later re-styled the Gand Union Canal after several mergers) starts at Braunston in Northampstonshire and goes south east to Daventry and Gayton. From Gayton there is a 5 miles branch to Northampton. The main line continues to Blisworth and Cosgrove. There is another branch at this point to Stoney Stratford, while the main line continues to Dinsford, King’s Langley, Rickmansworth (where there is a branch to Watford) and then to Uxbridge and Norwood before a junction with the River Thames at Brentford.

This is a distance of 90 miles.

The Marquis of Buckingham was the instigator of this scheme and in early 1792 employed James Barnes to survey a route. (Priestley's Navigable Rivers and Canals 1831 – reprinted by David and Charles 1969). The first Act of Parliament authorizing the formation of the company was passed in April 1793. This seems a remarkably short timescale for the survey alone, let alone getting an Act through Parliament.

In Faulkner's 'The Grand Junction Canal' it is reported that William Jessop was appointed as engineer for the construction of the canal working with James Barnes.

By 1794 the company obtained another Act permitting the construction of branches to Buckingham (from Stoney Stratford), Aylesbury (from Marsworth) and Wendover (from Bulbourne).

Yet another Act in 1795 provided for a new cut from Norwood to Paddington.

The Leicester and Northamptonshire Union Canal opened in 1797, while the Warwick and Birmingham Canal and the Warwick and Napton Canal opened in 1799 connecting Birmingham to London via the Grand Junction Canal and the Oxford Canal. This was follwed in 1814 by the opening of the Grand Union Canal between Norton Junction and Foxton finally completing the Leicester to London link. The Grand Union and the Leicester and Northamptonshire Union Canals were purchased by the Grand Junction Canal Company in 1894, but it was not until 1928 that the resutling network became known as the Grand Union Canal with 190 miles of waterway.

Problems raising funds for completion of this massive project meant that the proprietors had to return to Parliament on several occasions to re-structure their finances right through to 1819.

Of particular interest to my research is an Act of 1818, which permitted the company to abandon a section of canal “between Frogmoor Swing Bridge, in the parish of Hemel- Hempstead, and its junction with the Tail Water of Nash Mill” (p.308, para2)

The canal was diverted for a short distance along the course of the Rivers Bulbourne and Gade.

The original Grand Union was rather a small affair - a short length that connected the Leicester Union Canal at Gumley in Leicestershire with the Grand Junction Canal at Long Buckby in Northamptonshire – a distance of 45 miles. The line was surveyed by Benjamin Bevan Senior in 1810, and the relative Act of Parliament received Royal Assent in May 1810.

In subsequent decades the title of the ‘Grand Union’ came to embrace a much more extensive network of previously independent canals, that included the Leicester Unon Canal and the Grand Junction Canal.

The Warwick and Napton Canal was one of the waterways absorbed by the Grand Union. Authorised by an Act of Parliament in 1794, this 14 mile route began at the Warwick and Birmingham Canal at Budbrook, and passed through or close to Warwick, Leamington Priors, Radford and Stockton before joining the Oxford Canal at Napton. In 1962 Edwards listed the following canals as having been absorbed into the Grand Union

• Regents Canal and Limehouse Dock • Hertford Union Canal • Grand Junction Canal • Warwick and Napton Canal • Warwick and Birmingham Canal • Birmingham and Warwick Junction Canal • Leicester Navigation • Loughborough Navigation • Erewash Canal • Responsibility for 5.5 miles of the Oxford Canal between Napton and Braunston. There were also a number of branches from the main line • From the Regents Canal to Paddington Basin • The Slough Arm • The Wendover Arm • Aylesbury Arm • Northampton Arm • Welford Arm • Market Harborough Arm Edwards reported that the main line was still carrying regular traffic between London and Birmingham, and that there was a significant amount of barge traffic in the sections in the London area.

 
References:

• Priestley's Navigable Rivers and Canals by Joseph Priestley, Published by David & Charles, 1969, 1st Published 1831
  
• Inland Waterways of Great Britain and Ireland by Lewis A. Edwards, Published by Imray, Laurie, Norie & Wislon Ltd, 1962 edition, 1st published 1950
  
• The Grand Junction Canal by A.H. Faulkner, Published by David and Charles, 1972,