Question: Which four kingdoms did the Great Heathen Army invade?
Context: Repton Abbey was an Anglo-Saxon Benedictine abbey in Derbyshire, England.  Founded in the 7th century, the abbey was a double monastery, a community of both monks and nuns.  The abbey is noted for its connections to various saints and Mercian royalty; two of the thirty-seven Mercian Kings were buried within the abbey's crypt.  The abbey was abandoned in 873, when Repton was overrun by the invading Great Heathen Army. Hvitserk ("Hvitsärk") "White-Shirt" was one of the sons of the legendary 9th-century Norsemen Ragnar Lothbrok and his wife Aslaug.  He is attested to by the Tale of Ragnar's Sons ("Ragnarssona þáttr").  He is not mentioned in any source which mentions Halfdan Ragnarsson, one of the leaders of the Great Heathen Army which invaded the Kingdom of East Anglia in 865, or vice versa which consequently led some scholars to suggest that they are the same individual with "Hvitserk" being only a nickname. The Battle of Lüneburg Heath (also called the Battle of Ebstorf) was a conflict between the army of King Louis III of France and the Norse Great Heathen Army fought on 2 February 880 AD, at Lüneburg Heath in today's Lower Saxony. Ubba, also known as Hubba, Ubbe, and Ubbi, was a mid-ninth-century Viking chieftain and one of the commanders of the Great Army, a coalition of Norse warriors that in AD 865 invaded the Anglo-Saxon kingdoms of Northumbria, Mercia, East Anglia and Wessex. The four kingdoms of Daniel are four kingdoms which, according to the Book of Daniel, precede the "end-time" and the "Kingdom of God". The Abbey of Bury St Edmunds was once among the richest Benedictine monasteries in England, until the Dissolution of the monasteries in 1539.  It is in the town that grew up around it, Bury St Edmunds in the county of Suffolk, England.  It was a centre of pilgrimage as the burial place of the Anglo-Saxon martyr-king Saint Edmund, killed by the Great Heathen Army of Danes in 869.  The ruins of the abbey church and most other buildings are merely rubble cores, but two very large medieval gatehouses survive, as well as two secondary medieval churches built within the abbey complex. The Four Kingdoms of Andalusia (Spanish: "cuatro reinos de Andalucía" or, in 18th-century orthography, "quatro reynos del Andaluzia") was a collective name designating the four kingdoms of the Crown of Castile located in the southern Iberian Peninsula, south of the Sierra Morena.  These kingdoms were won from Muslim rule by the Christian monarchs of Castile during the "Reconquista"; as such, all four were former "taifas": the Kingdom of Córdoba was conquered in 1236, the Kingdom of Jaén in 1246, the Kingdom of Seville in 1248 and the Kingdom of Granada in 1492.  These four kingdoms occupied almost exactly the same territory as the present day Spanish autonomous community of Andalusia. The Great Viking Army or Great Danish Army, known by the Anglo-Saxons as the Great Heathen Army (OE: "mycel hæþen here"), was a coalition of Norse warriors, originating from Denmark (and likely also from Sweden and Norway) who came together under a unified command to invade the four Anglo-Saxon kingdoms that constituted England in AD 865. Halfdan Ragnarsson (Old Norse: "Hálfdan" ; or "Healfdene"; Old Irish: "Albann" ; died 877) was a Viking leader and a commander of the Great Heathen Army which invaded the Anglo-Saxon kingdoms of England, starting in 865.  According to the tradition recorded in the Norse sagas he was one of the sons of Ragnar Lodbrok, and his brothers included Björn Ironside, Ivar the Boneless, Sigurd Snake-in-the-Eye and Ubba.  He was the first Viking King of Northumbria and a pretender to the throne of Kingdom of Dublin.  He died at the Battle of Strangford Lough in 877 trying to press his Irish claim. At the Battle of Edington an army of the Anglo-Saxon kingdom of Wessex under Alfred the Great defeated the Great Heathen Army led by Guthrum on a date between 6 and 12 May AD 878, soon resulting in the Treaty of Wedmore later the same year.  The primary sources locate the battle at ""Ethandun"" or ""Ethandune"", and until a scholarly consensus identified its location with the present-day Edington in Wiltshire it was known as the Battle of "Ethandun", a name which continues to be used.
Answer: Northumbria, Mercia, East Anglia and Wessex