Earl of Northumbria in the context of Morcar

Tostig Godwinson (c. 1029 – 25 September 1066) was an Anglo-Saxon Earl of Northumbria and brother of King Harold Godwinson. After being exiled by his brother, Tostig supported the Norwegian king Harald Hardrada's invasion of England, and was killed alongside Hardrada at the Battle of Stamford Bridge in 1066.

The Rulers of Bamburgh (Old English: Bebbanburh; Old Irish: Dún Guaire; Brittonic: Din Guairoi) were significant regional potentates in what is now northern England and south-eastern Scotland during the Viking Age. Sometimes referred to in modern sources as the Earldom of Bamburgh, their polity existed for roughly two centuries, beginning after the attacks on the Anglo-Saxon Kingdom of Northumbria by the Vikings in the later ninth century, and ending after the Norman Conquest later in the eleventh century. In Scottish and Irish sources of the period the Bamburgh 'earldom' is referred to as the kingship of the Northern English (or the North English kingdom), or simply of the 'Saxons'.

In essence, Bamburgh and the surrounding region (the former realm of Bernicia), the northern component of Northumbria, was ruled in succession by a shadowy series of 'kings', 'earls' (Latin duces) and 'high-reeves' (from Old English heah-gerefa). Most of these were descended from Eadwulf I of Bamburgh, thereafter called the Eadwulfings or House of Bamburgh. Several of these men commanded the whole of Northumbria, and their jurisdiction is also sometimes referred to also as the earldom of Northumbria (not to be confused with the southerly 'official' ealdordom of Northumbria based at York).

Eadwulf II (fl. AD 968–970), nicknamed Evil-child (Old English: Yfelcild), was ruler of Bamburgh in the latter half of the tenth century. Although Eadwulf is sometimes described as the Earl of Northumbria, he ruled only a northern portion of Northumbria, a polity centred on Bamburgh that once stretched from the Firth of Forth to the River Tees.

Uhtred of Bamburgh (Uhtred the Bold—sometimes Uchtred; died ca. 1016) was ruler of Bamburgh and from 1006 to 1016 the ealdorman of Northumbria. He was the son of Waltheof I, ruler of Bamburgh (Bebbanburg), whose family, the Eadwulfingas, had ruled the surrounding region for over a century. Uhtred's death by assassination was described in De obsessione Dunelmi and has been interpreted as the beginning of a blood feud. Lest he be confused with Uhtred, the son of Eadwulf I of Bamburgh, he historically has been referred to as Uhtred the Bold.

The Lords of Coucy (French: sires de Coucy or seigneurs de Coucy), also spelt Couci, were a medieval lordship based on the barony of Coucy located in the current commune of Coucy-le-Château-Auffrique, Picardy. The château de Coucy was founded by Hervé, archbishop of Rheims, and remained under the fluctuating control of these archbishops for some time until probably the later part of the 10th century. The exact status of Coucy becomes obscure for nearly a century before the emergence of Lord Aubrey, Earl of Northumbria. Though the Lords of Coucy were entitled to the title of baron, they preferred the rarer Sire.

The lords of Coucy became, especially in the 13th century, one of the most powerful sub-comital magnates in western Europe and forged links with royal families, such as those of France, England, Scotland and Austria. The title was eventually absorbed at the end of the 14th century by Louis of Valois, Duke of Orléans.