The Saxons of England were said to come from Cerdic of Wessex, who was the first in the line of many Wessex monarchies. His name is tied to the genealogy of Alfred the Great, who was one of the greatest kings of Wessex and would begin to unite the country.
Becoming King of Wessex
It is important to note that Wessex, as we have come to know it later on during the Saxon period, did not exist. When Cerdic of Wessex arrived, he was dealing with the post-roman empire that had ruled over England for centuries. After Rome's fall, there were many territorial disputes, and people began to form smaller city-states that would result in many different factions and much in-fighting.
The information we have regarding Cerdic of Wessex is when he landed in modern-day Hampshire in 495 with his son Crynric and five ships. According to the main source, the Angl-Saxon Chronicle, Cerdic fought and defeated the Britoonic king Natanleod in 519. The battle resulted in Natanleod's death, which opened a pathway for Cerdic to take control.
The conquest of the Isle of Wight is mentioned among his campaigns, and it later was given to his kinsmen, Stuf and Wihtgar. Cerdic is said to have died in 534, succeeded by his son Cynric.
Was Cerdic a Real Historical Figure
Here is what Wikipedia says about this topic:
The early history of Wessex in the Chronicle has been considered unreliable, with duplicate reports of events and seemingly contradictory information. David Dumville has suggested that Cerdic's true regnal dates are 538–554. Some scholars suggest that Cerdic was the Saxon leader defeated by the Britons at the Battle of Mount Badon probably fought in 490 (and possibly later, but not later than 518). This cannot be the case if Dumville is correct, and others assign this battle to Ælle or another Saxon leader, so it appears likely that the origins of the kingdom of Wessex are more complex than the version provided by the surviving traditions.
Some scholars have gone so far as to suggest that Cerdic is purely a legendary figure, but this is a minority view. The Anglo-Saxon Chronicle, the earliest source for Cerdic, was put together in the late ninth century; though it probably does record the extant tradition of the founding of Wessex, the intervening 400 years mean that the account cannot be assumed to be accurate. The annals of the Anglo-Saxon Chronicle, along with the genealogical descents embedded in that source's accounts of later kings, describe Cerdic's succession by his son Cynric. However, the Genealogical Regnal List that served as a preface to the Chronicle manuscripts instead interposes a generation between them, indicating that Cerdic was the father of Creoda and the grandfather of Cynric.
Descent from Cerdic became a necessary qualification for later kings of Wessex, and he was claimed ancestor of Ecgberht, King of Wessex, progenitor of the English royal house, and subsequent rulers of England and Britain.
It is impossible to prove Cerdic of Wessex's existence due to the lack of evidence and primary source material. Most of the evidence we have is based on legend, and the legend was believed to be true by future kings of Wessex.
The reality is that he probably did exist, and some of what has been said about him is probably true. However, it is possible that many of the facts about him are inaccurate and should be viewed skeptically.
Future kings of Wessex acknowledged his existence, and they lived closer to his lifetime than modern historians, so it is possible that oral tradition is how he was remembered.