Offa of Mercia in the context of "Bedford"

This list of kings and reigning queens of the Kingdom of England begins with Alfred the Great, who initially ruled Wessex, one of the seven Anglo-Saxon kingdoms which later made up modern England. Alfred styled himself king of the Anglo-Saxons from about 886, and while he was not the first king to claim to rule all of the English, his rule represents the start of the first unbroken line of kings to rule the whole of England, the House of Wessex.

Arguments are made for a few different kings thought to have controlled enough Anglo-Saxon kingdoms to be deemed the first king of England. For example, Offa of Mercia and Egbert of Wessex are sometimes described as kings of England by popular writers, but it is no longer the majority view of historians that their wide dominions were part of a process leading to a unified England. The historian Simon Keynes states, for example, "Offa was driven by a lust for power, not a vision of English unity; and what he left was a reputation, not a legacy." That refers to a period in the late 8th century, when Offa achieved a dominance over many of the kingdoms of southern England, but it did not survive his death in 796. Likewise, in 829 Egbert of Wessex conquered Mercia, but he soon lost control of it.

The English penny (plural "pence"), originally a coin of 1.3 to 1.5 grams (0.042 to 0.048 troy ounces; 0.046 to 0.053 ounces) pure silver, was introduced c. 785 by King Offa of Mercia. These coins were similar in size and weight to the continental deniers of the period and to the Anglo-Saxon sceats which had preceded it.

Throughout the period of the Kingdom of England, from its beginnings in the 9th century, the penny was produced in silver. Pennies of the same nominal value, 1⁄240 of a pound sterling, were in circulation continuously until the creation of the Kingdom of Great Britain in 1707.

Offa's Dyke (Welsh: Clawdd Offa) is a large linear earthwork that roughly follows the border between England and Wales. The structure is named after Offa, the Anglo-Saxon king of Mercia from 757 to 796, who is traditionally believed to have ordered its construction, although modern archaeological evidence shows far earlier origins and its original purpose is debated.

It delineated the border between Anglian Mercia and the Welsh kingdoms (such as Powys) by the time of its completion, but when begun (carbon-dated to 430AD) it separated the Brytons of the Decangi, Cornovi and Dobunni from the Western Ordovices, Demetae and Silures.

Ecgberht (died 839), also spelled Egbert, Ecgbert, Ecgbriht, Ecgbeorht, and Ecbert, was King of Wessex from 802 until his death in 839. His father was King Ealhmund of Kent. In the 780s, Ecgberht was forced into exile to Charlemagne's court in the Frankish Empire by the kings Offa of Mercia and Beorhtric of Wessex, but on Beorhtric's death in 802, Ecgberht returned and took the throne.

Little is known of the first 20 years of Ecgberht's reign, but it is thought that he was able to maintain the independence of Wessex against the kingdom of Mercia, which at that time dominated the other southern English kingdoms. In 825, Ecgberht defeated Beornwulf of Mercia, ended Mercian Supremacy at the Battle of Ellandun, and proceeded to take control of the Mercian dependencies in southeastern England. In 829, he defeated Wiglaf of Mercia and drove him out of his kingdom, temporarily ruling Mercia directly. Later that year Ecgberht received the submission of the Northumbrian king at Dore. The Anglo-Saxon Chronicle subsequently described Ecgberht as a bretwalda or 'wide-ruler' of Anglo-Saxon lands.

Mercia (/ˈmɜːrsiə, -ʃə/) was one of the principal kingdoms founded at the end of Sub-Roman Britain; the area was settled by Anglo-Saxons in an era called the Heptarchy. It was centred on the River Trent and its tributaries, in a region now known as the Midlands of England.

The royal court moved around the kingdom without a fixed capital city. Early in its existence Repton seems to have been the location of an important royal estate. According to the Anglo-Saxon Chronicle, it was from Repton in 873–874 that the Great Heathen Army deposed the King of Mercia. Slightly earlier, King Offa seems to have favoured Tamworth. It was there where he was crowned, and where he resided during multiple Christmases.