Barnet Union comprised the following Hertfordshire parishes: Chipping Barnet, East Barnet, Elstree, Ridge, Shenley and Totteridge, together with the following in Middlesex: Finchley, Friern Barnet,...

Berkhamsted Union comprised the following Hertfordshire parishes: Aldbury, Great Berkhamsted, Little Gaddesden, Northchurch, Puttenham, Tring and Wigginton, together with Nettleden (Buckinghamshire...

Bishops Stortford Union comprised the following parishes: Albury, Bishops Stortford, Braughing, Much Hadham, Little Hadham, Brent Pelham, Furneux Pelham, Stocking Pelham, Sawbridgeworth, Thorley an...

Hemel Hempstead Union consisted of the following parishes:
Bovingdon, Flamstead, Flaunden, Great Gaddesden, Hemel Hempstead, King's Langley, plus Markyate, created in 1897. The Poor Law Institutio...

Hertford Union consisted of the following parishes:
Little Amwell, Aston, Bayford, Bengeo, Benington, Little Berkhampstead, Bramfield, Brickendon, Datchworth, Hertford (All Saints, St John and St A...

St Albans Union comprised the following parishes: Harpenden, Redbourn, St Albans, St Michael, St Peter, St Stephen, Sandridge, Wheathampstead. The Poor Law Institution, built in 1835, was called 'O...

Ware Union comprised the following parishes: Broxbourne, Eastwick, Gilston, Great Amwell, Great Munden, Hoddesdon, Hunsdon, Little Munden, Standon, Stanstead Abbots, Stanstead St Margaret, Thundrid...

Watford Union comprised the following parishes: Abbots Langley, Aldenham, Bushey, Oxhey (created in 1906), Rickmansworth, Sarratt, Watford. The Poor Law Institution in Vicarage Road was called 'Shr...

Welwyn Union comprised the following parishes: Ayot St Lawrence, Ayot St Peter, Digswell and Welwyn. In October 1921 the Union became part of Hatfield Union (see BG/HAT). The Poor Law Institution, ...