Wiglaf (died 839) was King of Mercia from 827 to 829 and again from 830 until his death. His ancestry is uncertain: the 820s were a period of dynastic conflict within Mercia and the genealogy of several of the kings of this time is unknown. Wigstan, his grandson, was later recorded as a descendant of Penda of Mercia, so it is possible that Wiglaf was descended from Penda, one of the most powerful seventh-century kings of Mercia.
Wiglaf succeeded Ludeca, who was killed campaigning against East Anglia. His first reign coincided with the continued rise of the rival Anglo-Saxon kingdom of Wessex under Egbert. Egbert drove Wiglaf from the throne in 829, and ruled Mercia directly for a year. Wiglaf recovered the kingdom in 830, probably by force although it may be that Wiglaf remained subject to Egbert's overlordship. Mercia never regained the south-eastern kingdoms, but Berkshire and perhaps Essex came back into Mercian control. The causes of the fluctuating fortunes of Mercia and Wessex are a matter of speculation, but it may be that Carolingian support influenced both Egbert's ascendancy and the subsequent Mercian recovery. Although Wiglaf appears to have restored Mercia's independence, the recovery was short-lived, and later in the century Mercia was divided between Wessex and the Vikings.
Mercia had been the dominant Anglo-Saxon kingdom for most of the 8th century, with Offa, who died in 796, the most powerful king of his time. Coenwulf, who took the Mercian throne shortly after Offa's death, was able to retain Mercian influence in the kingdoms of Kent, East Anglia and Essex, and made frequent incursions across Offa's Dyke into what is now Wales. However, Coenwulf's death, in 821, marked the beginning of a period in which the political map of England was dramatically redrawn. Although one eleventh-century source claims that Coenwulf's son, Cynehelm, briefly succeeded to the throne, it is more likely that Ceolwulf, Coenwulf's brother, was the next king. He reigned for only two years before being deposed.
The next king, Beornwulf, was of no known royal line, though it has been conjectured on the basis of the common initial letter B that he was connected to the later kings Beorhtwulf and Burgred. It was probably Beornwulf whose defeat of the kingdom of Powys and destruction of the fortress of Deganwy are recorded in a Welsh chronicle, the Brut y Tywysogion, in 823, and it is clear that Mercia was still a formidable military power at that time. However, in 825 Beornwulf was decisively defeated by Egbert of Wessex at the battle of Ellendun, and died the next year in an unsuccessful invasion of East Anglia. His successor, Ludeca, of unknown lineage, also invaded East Anglia, and like Beornwulf died while campaigning there, in 827. These defeats, in rapid succession, are likely to have exacerbated the apparent dynastic contention for Mercian royal authority. Outside Mercia, the power of the kingdom of Wessex, to the south, was strong and growing when Wiglaf came to the throne.
A medieval tradition preserved at Evesham records that Wiglaf's grandson Wigstan was a descendant of Coenred, who was a grandson of Penda. Wigstan's grandfathers were Wiglaf and Ceolwulf I; the tradition might be interpreted to mean that Wiglaf descended from Penda, but it might also be Wiglaf's wife, Cynethryth, who was descended from Penda. Cynethryth's name is known from two of Wiglaf's charters, dated 831 and 836, and historian Pauline Stafford notes that her name "seems to hark back to the kin of Coenwulf if not earlier royal lines", but as with Wiglaf himself, nothing certain is known of her ancestry. A different connection is mentioned in the medieval Life of St. Wigstan, which asserts that the "B" and "W" families were related.
Known descendants of Wiglaf include his son, Wigmund, and his grandson, Wigstan, both of whom share the "Wig-" at the start of his name; alliterative family names are frequent in Anglo-Saxon dynasties and are often thought to suggest possible kinship. Other possible descendants of Wiglaf include the last Mercian king, Ceolwulf II. A large number of duces or praefecti (ealdormen) with similar names are found as witnesses in Mercian charters of the late 8th and early 9th centuries, including Wigbald, Wigberht, Wigcga, Wigferth, and Wigheard, but there is no evidence beyond the similarity of names to show that there was a relation between these nobles.
The Anglo-Saxon Chronicle records Wiglaf's accession in the entry for 827 (erroneously recorded under the year 825). The entry reads "Her Ludecan Myrcna cing 7 his fif ealdormenn mid him man ofsloh, 7 Wiglaf feng to rice", which means "Here Ludeca, King of Mercia, was killed, and his five ealdormen with him, and Wiglaf succeeded to the kingdom". In 829, Egbert of Wessex successfully invaded Mercia and drove Wiglaf from his throne. The immediate consequence of Egbert's defeat of Beornwulf in 825 at the battle of Ellendun had been the loss of Mercian control over the south-eastern kingdoms of Kent, Sussex, Essex and East Anglia; Beornwulf's and Ludeca's disastrous military expeditions against East Anglia in 826 and 827 also confirmed Mercia's loss of control of that kingdom. Egbert's defeat of Wiglaf in 829 completed his domination of southern England, and Egbert went on to receive the submission of Eanred of Northumbria at Dore, on the northern border of Mercia, later that year. These events led the anonymous scribe who wrote the Anglo-Saxon Chronicle to describe Egbert as the eighth bretwalda, or "Ruler of Britain".
Egbert remained in control of Wessex until some time in 830. He was in power there long enough to issue coins (struck in London) bearing the title "Rex M", for "Rex Merciorum", or "King of Mercia".
A charter of 831, which Wiglaf calls "the first year of my second reign", was issued at Wychbold near Droitwich; it is significant that Wiglaf makes no reference to any overlordship of Egbert's in this charter, issued within a year of his recovery of power, and that he acknowledges his temporary deposition. In East Anglia, King Æthelstan minted coins, possibly as early as 827, but more likely c. 830 after Egbert's influence was reduced with Wiglaf's return to power in Mercia. This demonstration of independence on East Anglia's part is not surprising, as it was probably Æthelstan who was responsible for the defeat and death of both Beornwulf and Ludeca.
Both Wessex's sudden rise to power in the late 820s, and the subsequent failure to retain this dominant position, have been examined by historians looking for underlying causes. Dynastic uncertainty has been suggested as the reason for Mercia's collapse; the 820s were certainly years of instability in the royal line. The lack of detailed information about Mercian and Wessex administration makes other theories hard to evaluate: for example it has been suggested that the West Saxons had a stable tributary system that contributed to its success, or that Wessex's mixed Saxon and British population, natural frontiers, and capable administrators were key factors.
Another proposed explanation for the events of these years is that Wessex's fortunes were to some degree dependent on Carolingian support. The Rhenish and Frankish commercial networks collapsed at some time in the 820s or 830s, and in addition, a rebellion broke out in February 830 against Louis the Pious, the first of a series of internal conflicts that lasted through the 830s and beyond. These distractions may have reduced Louis's ability to support Egbert. In this view, the withdrawal of Frankish influence would have left East Anglia, Mercia and Wessex to find a balance of power not dependent on outside aid.
Wiglaf's recovery, however, was not complete. Egbert's influence was certainly reduced after 830, but Mercia never recovered control of the south-east, except possibly for Essex; and East Anglia remained independent. It appears that Wulfred, the archbishop of Canterbury at the time of Egbert's victory, remained loyal to Mercia: his coinage terminates when Egbert's Kentish coinage begins; and since a charter of 838 shows Egbert agreeing to return property to the church in Canterbury it is evident that he had seized property from the church earlier. Æthelwulf, Egbert's son, was king of Kent during his father's reign, and fear of continuing Mercian influence in Kent may have been the reason he gave estates to Christ Church, Canterbury.
Charters survive from Wiglaf's reign; these were documents which granted land to followers or to churchmen, and were witnessed by the kings who had power to grant the land. One such charter of Wiglaf's, granting privileges to the monastery of Hanbury in 836, does not exempt the monks from the duty of constructing ramparts, indicating a concern for defence. Wessex charters do not begin to show such exemptions until 846. These clauses are explained by the increasing Viking presence throughout Britain: Viking raids had begun at least as early as 793, Viking armies were in Kent by 811, and from 835 Viking raids were a concern for the kings of Wessex.
The 836 charter also contains an early reference to the trimoda necessitas, the set of three obligations that kings of the era placed on their subjects. These duties were the building of royal residences, the obligation to pay feorm, or food-rent, to the king, and hospitality to the king's servants. The privileges granted came at a cost: Wiglaf and one ealdorman received life interests in estates, and another ealdorman was paid six hundred shillings in gold. It is perhaps notable that in common with many other Mercian charters of the 9th century, this grant is of privileges rather than land: the chronicler Bede had commented a century earlier that excessive grants of land to monasteries were leaving kings without land to grant to the nobility, and the Mercian kings may have been responding to this problem.
The date of Wiglaf's death is not given directly in any of the primary sources, but it can be determined from the known chronology of his successors. The Anglo-Saxon Chronicle records that Burgred was driven out of Mercia by the Vikings in 874, after a reign of twenty-two years, and charter evidence indicates that Burgred succeeded in the first half of 852. A regnal list credits his predecessor, Beorhtwulf, with a reign of thirteen years, which is consistent with date references in his charters. Hence it would appear that Wiglaf's reign ended in 839. A tradition records the death of Wigstan in 849, and refers to Wigstan's father, Wigmund, the son of Wiglaf, as having been king, but this is the only evidence for Wigmund having reigned and must be regarded with suspicion. The descent of Beorhtwulf is not known, but it appears that dynastic tension was a continuing factor in the Mercian succession, in contrast to Wessex, where Egbert established a dynasty that lasted with little disturbance throughout the 9th century.
Wiglaf was buried at Repton, in a crypt which still can be seen. The monastery church on the site at that time was probably constructed by Æthelbald of Mercia to house the royal mausoleum; other burials there include that of Wigstan, Wiglaf's grandson. The vault and columns in the crypt are not original and may date from Wiglaf's time rather than Aethelbald's.