807 - Death of of King Arthwyr of Ceredigion.

808 - Death of Kings Rhain of Dyfed and Cadell of Powys.

809 - Death of Archbishop Elfoddw of Gwynedd.

810 - St. Davids is burnt.

811 - Death of King Owain of Dyfed. His son-in-law, Hyfaidd takes the throne.

812 - Degannwy, the capital of Gwynedd, is struck by lighning and burnt to the ground.

813 - King Cynan Dindaethwy of Gwynedd meets Hywel Farf-Fehinog in battle. Hywel is defeated.

814 - Prince Gryffydd of Powys is slain through the treachery of his brother Elisedd. Hywel Farf-Fehinog invades Anglesey and attacks his rival, King Cynan Dindaethwy of Gwynedd. Hywel is victorious, proclaims himself King and drives Cynan from the Gwynedd shores.

815 - The Kingdom of Cerniw is raided by King Egbert of Wessex and his Saxon armies from East to West.

816 - King Hywel Farf-Fehinog of Gwynedd is attacked by his rival, King Cynan Dindaethwy, on Anglesey. Cynan is killed. The English successfully invade Rhufoniog and also ravage the Snowdonia Mountains.

818 - King Coenwulf of Mercia raids Dyfed.

821 - King Coenwulf of Mercia dies in Basingwerk while preparing for another assault on Powys.

823 - The Mercians invade Powys, but are beaten back by King Cyngen. They also destroy the Gwynedd capital, Degannwy.

825 - Death of King Hywel Farf-Fehinog of Gwynedd. The kingdom is seized by King Merfyn Frych of Ynys Manaw (and South Rheged), grandson of his old rival, Kinf Cynan Dindaethwy. The men of Cerniw make a push into Saxon Devon and the two armies clash at the Battle of Gafelford (Camelford or Galford). The Cornish are probably victorious.

c.830 - Nynniaw, Abbot of Bangor Fawr, compiles the Historia Brittonum.

831 - Death of Bishop Sadyrnfyw of St. Davids.

836 - With King Merfyn Frych of Ynys Manaw absent in his newly acquired Kingdom of Gwynedd, Irish Viking invaders manage to take over the island.

838 - The British of Cerniw join forces with the Vikings and attack Saxon Wessex. King Egbert defeats them at the Battle of Hingston Down.

840 - Nobis becomes Bishop of St. Davids.

844 - Death of King Merfyn Frych of Gwynedd. His son, Rhodri Mawr, succeeds to the throne.

848 - The armies of Brycheiniog and Gwent clash at the Battle of Ffinnant. King Ithel of Gwent is killed in the fighting.

c.850 - "Eliseg's Pillar" is erected in Llantysilio-yn-Ial by King Cyngen of Powys as a memorial to his great grandfather King Elisedd (or Eliseg) and the power of the Powysian dynasty. Bishop Censteg of Dingerein (Cerniw) accepts the authority of Archbishop Ceolnoth of Canterbury. King Rhodri Mawr of Gwynedd develops Llanbedrgoch, and possibly other sites, as fortified settlements to protect the Welsh against Viking raids.

853 - Mercia and Wessex attack Powys.

854 - King Cyngen of Powys dies on a pilgrimage to Rome. His throne is seized by his nephew, King Rhodri Mawr of Gwynedd, and his sons expelled.

855 - Anglesey is ravaged by Dublin Vikings.

856 - King Rhodri Mawr of Gwynedd & Powys repels a major Viking invasion of Wales and kills their king, Gorm.

871 - Dumbarton, capital of King Artgal of Strathclyde, is destroyed by King Olaf of Norse Dublin and his Viking warriors.

872 - Death of King Gwrgon of Seisyllwg by drowning. The throne is taken by his son-in-law, King Rhodri Mawr of Gwynedd & Powys. King Artgal of Strathclyde is slain through the connivance of King Constantine I of Alba and his Viking allies. Artgal's son, Run, succeeds to the Strathclyde throne.

874 - Death of Bishop Nobis of St. Davids.

876 - Death of Dungarth, the last King of Cerniw. He was drowned during a hunting accident and buried at St. Cleer.

877 - The Vikings invade Wales once more and King Rhodri Mawr of Gwynedd, Powys & Seisyllwg is forced to flee to Ireland.

878 - King Rhodri Mawr of Gwynedd, Powys and Seisyllwg returns to his kingdoms, but is killed fighting the Mercians of King Ceolwulf II. His kingdoms are divided amongst his three sons, Anarawd, Merfyn and Cadell respectively. The Vikings winter in Dyfed. Death of King Run of Strathclyde. His son, Eochaid, succeeds to the throne and allies himself with his mother's cousin, King Giric of Alba. The two rule all Scotland together as joint-monarchs.

880 - King Anarawd of Gwynedd initiates a revenge attack on the Mercian armies and defeats them on the River Conwy.

c.881 - King Anarawd of Gwynedd and his brothers begin extensive military campaigns to quell resistance in Powys and Seisyllwg.

885 - Asser, a relative of Nobis, Bishop of St. Davids, is summoned to the court of King Alfred of England. He agrees to spend six months of the year in the King's service. Asser helps to enhance the literary status of the English Court and also to negotiate the recognition of Alfred as overlord of the South Welsh Kings.

c.885 - Kings Hyfaidd of Dyfed, Elisedd of Brycheiniog and Hywel of Glywysing are harassed by the armies of King Anarawd of Gwynedd. They seek the protection of King Alfred of England and submit to his overlordship. Anarawd seeks an alliance with the Norse Kings of York.

889 - Kings Eochaid and Giric of Alba, Strathclyde & the Picts are deposed by Viking invaders. The former's cousin takes the throne as King Donald II. The end of independent Strathclyde rule.

890 - King Donald II of Alba expels the British aristorcracy of Strathclyde. They flee south to North Wales.

893 - Death of King Hyfaidd of Dyfed. Battle of Buttington at which the Welsh under King Merfyn of Powys, and the English under King Alfred the Great, besiege and defeat the Danish army of Prince Hastein.

c.893 - Asser, the Welshman, is made Bishop of Sherborne.

894 - King Anarawd of Gwynedd's shaky alliance with the Vikings collapses. His kingdom is ravaged by the Norsemen. Anarawd is forced to ask for help from King Alfred of England and submits to his overlordship. Alfred imposes oppressive terms and forces Anarawd to confirmation in the Christian Church with Alfred as godfather. Bishop Asser of Sherborne, writes his "Life of King Alfred"

895 - King Anarawd of Gwynedd is supplied with English troops to assist in his reconquest of Seisyllwg. He is successful and his brother, King Cadell, is finally able to take his rightful place on the Seisyllwg throne.

896 - Brycheiniog and Gwent are ravaged by Haesten and his Viking pirate army.

c.900 - King Tewdr of Brycheiniog establishes his court on a crannog in the middle of Llangorse Lake. Llanbedrgoch transforms from a fortified settlement into a trading centre.

902 - The Norsemen are expelled from Dublin. They attempt to settle in Seisyllwg, but are driven off northwards.

903 - The Dublin Vikings, under Prince Ingimund, capture Osfeilion in Anglesey, but are quickly repulsed by Prince Clydog and settle in the Wirral and around Kelston & Axton in Flintshire instead.

904 - Marriage of Prince Hywel Dda of Seisyllwg to Princess Elen of Dyfed. Death of the latter's father, King Llywarch. The throne of Dyfed is claimed by Llywarch's brother, Rhodri, but he is probably forced to flee from Hywel's armies.

905 - Rhodri, nominally King of Dyfed, is caught and executed, at Arwystli, probably by his neice's husband, Hywel Dda. Hywel claims the throne of Dyfed. Norse settlers from Flintshire and the Wirral attack the city of Chester, but are beaten off.

909 - Death of Asser, the Welsh Bishop of Sherborne.

c.910 - Death of King Cadell of Seisyllwg. His son, King Hywel Dda unites Seisyllwg and Dyfed to form the Kingdom of Deheubarth.

914 - A Vikings fleet from Brittany harries the South Welsh Coast and moves up the Severn. They capture Bishop Cyfeilliog of Ergyng, but are driven out by Saxon levies from Hereford and Gloucester.

916 - Death of King Anarawd of Gwynedd. English raiders attack the court of King Tewdr of Brycheiniog at Llangorse and make off with the Queen and thirty-three of her courtiers.

917 - Brycheiniog is ravaged by the armies of Lady Aethelflaed of the Mercians in revenge for the killing of the, now unknown, Abbot Ecgberht.

918 - King Idwal Foel of Gwynedd and King Hywel Dda and Prince Clydog of Deheubarth submit to the overlordship of King Edward the Elder of England. The Vikings raid Anglesey.

921 - Foundation of Cledemutha.

927 - Kings Hywel Dda of Deheubarth and Owain of Glywysing & Gwent submit to the overlordship of King Athelstan of England at Hereford. The border between England and Wales is set at the River Wye.

928 - King Hywel Dda of Deheubarth, Gwynedd & Powys begins the codification of Welsh customary law.

929 - King Hywel Dda of Deheubarth goes on a pilgrimage to Rome.

931 - King Morgan Hen of Glywysing & Gwent submits to the overlordship of King Athelstan of England and attends his court with Kings Hywel Dda of Deheubarth and Idwal Foel of Gwynedd.

934 - King Tewdr of Brycheiniog attends the court of King Athelstan of England and signs English Land Charters. Kings Hywel Dda of Deheubarth, Idwal Foel of Gwynedd and Morgan Mwynfawr of Morgannwg are compelled to accompany Athelstan on his campaign against King Constantine II of the Scots.

937 - King Athelstan of England defeats a combined Northern Army under Kings Olaf of Dublin, Constantine II of Scots and Owain of Strathclyde at the Battle of Brunanbury. Though none of the British monarchs appear to have taken part, the people of Strathclyde were a major contingent under their Scottish King. The battle finally ends all British hope of driving the Saxons from their shores.

c.937 - King Idwal Foel of Gwynedd distances himself from his English overlord. The British begin to use the term "Cyrmry" to speak of themselves.