- Family history Guide to tracing family trees.
- The 'Fed' South Wales Miners' Federation (SWMF)
- Flander-Wales Migration 12th century Fleming communities in south Pembrokeshire.
- Genealogy Guide to tracing family trees.
- Giraldus Cambrensis (Gerald of Wales) Cleric and scholar whose chronicles shaped perceptions of Wales for centuries.
- Y Gododdin Poem attributed to Aneirin (late 6th century).
- Y Gogynfeirdd Name for courtly Welsh bards or poets of the 12th to early 14th centuries.
- Gold mining Dolaucothi mine in Carmarthenshire was seized upon by the Romans for its gold resources.
- Gorsedd of the Bards Society of poets, writers, musicians, artists and individuals who have made a notable contribution to the Welsh nation.
- Government of Wales Act (1998) Act to ensure that the National Assembly treats the Welsh and the English languages equally.
- Great Orme copper mines Mines dating back 4,000 years to the Bronze Age.
- Greenham Common RAF base in Berkshire where a Women's Peace Camp was established to protest against nuclear weapons being sited on the base.
- Griffith Jones 18th century minister who organised circulating schools in Carmarthenshire.
- Gwenllian Morgan Wales' first female mayor.
- Gwyneth Morgan Daughter of Courtenay Morgan, 1st Viscount Tredegar. She was found dead aged 29 in the River Thames.
- Gwynfor Evans Welsh politician and the first Member of Parliament to represent Plaid Cymru at Westminster.
- Harald Hardrada King of Norway 1045-66, invaded England in 1066 but was killed in battle by King Harold II's army at the Battle of Stamford Bridge.
- Harold Godwinson Also known as Harold II. Widely regarded as the last Anglo-Saxon King of England before the Norman Conquest.
- Hedd Wyn Merionethshire farmer and Welsh language poet of World War I.
- Henry IV Took the English crown from Richard II, beginning the Lancastrian dynasty.
- Henry V Born at Monmouth, Wales, he reigned as King of England from 1413 to 1422.
- Henry VI The only child of Henry V and Catherine of Valois.
- Henry VII Also known as Henry Tudor - the first Tudor king.
- Henry VIII Infamous Tudor monarch responsible for passing the Acts of Union of 1536 and 1543 that legally incorporated Wales into England and banned Welsh monoglot speakers from public office.
- Henry Scudamore Sheriff of Herefordshire married to Owain Glyndwr's daughter Alys.
- House of Lancaster Branch of the English royal House of Plantagenet one of the opposing factions involved in the Wars of the Roses.
- House of York Branch of the English royal House of Plantagenet.
- Hywel Dda / Law of Wales Codified between 942 and 950, when Hywel Dda (Hywel the Good) was king of most of Wales.
- Phil Carradice blogs on Hywel Dda and his laws and reforms, laid down in the mid-10th century.
- Iestyn ap Gwrgant Last ruler of the Welsh kingdom of Morgannwg.
- Immigration Wales' population has regularly shifted and changed over the ages.
- Industrial Revolution The industrial revolution saw massive migration into Wales.
- Iolo Morganwg Responsible for the establishment of the Gorsedd of the Bards
- Ireland-Wales migration The Irish began arriving in Wales in the 1840s.
- Italy-Wales migration In the wake of the industrial revolution, Italian people settled in Wales to create businesses and services for new workers.
- Ivor Novello Blog on this remarkable Welsh man who was an accomplished composer, singer and actor.
- Jasper Tudor (Earl of Pembroke) Half-brother to King Henry VI.
- John Dee History blog on 16th century mathematician, teacher of navigation, astrologer, astronomer, an alchemist and, by all accounts, a magician too.
- John of Gaunt Member of the House of Plantagenet.
- John Price Wrote Yn Y Lhyvr Hwnn 'In This Book' which was the first book printed in Welsh.
