Firstly, a disclaimer. St George is not strictly English -- he's Turkish. But he's been considered the patron of England since 1415, and England's flag even sports his cross. So he's English by adoption.
Saint George was a fourth century martyr, an ancient patron of soldiers, who had long been popular in the Eastern Orthodox Church. When an edict was issued to kill all Christians in the Emperor Diocletian’s army, George proclaimed his faith and refused to be converted. He gave away his money to the poor and was martyred for his faith.
Later legends had him slaying a dragon, which some say is actually symbolic of him defeating Satan and remaining true to his faith.
Posterity has it that the crusaders had a vision of St. George at the siege of Antioch during the First Crusade (1096-1099) which was attributed to the defeat of the Saracens. Richard I later placed his army under the protection of St. George during the Third Crusade (1189–1192) which then boosted George's prestige back in Britain. His feast day, April 23, was made a holiday in 1222 and Edward III adopted him as his own personal saint.
By 1415 Archbishop Chichele made his feast day one of the major events of that year, and St George emerged as England's principle patron saint.
St Mary, Chediston, Suffolk , referencing Shakespeare.
"Cry 'God for Harry, England, and Saint George!'" Henry V.
George the Name:
The name George is the Anglicised form of the Greek name Γεωργιος (Georgios). The name is taken from the Greek word γεωργός (georgos) "a farmer, husbandman" or, more literally, "earth-worker," derived from γῆ (ge) "earth" and έργο (ergo) "to work."
Thanks to the prominence of St George, the name ranked in the Top 10 most popular boys' names from the 1530s to the 1930s. Along the way, it was also born by six kings and several princes -- including the most recent one!
The diminutives Georgie and Geordie were established by the 18th century, the latter of which was so common in Northern England, it is now used as a byword for a person from Newcastle (cf. Paddy and Taffy).
The many other British forms include the Scots Gaelic Deòrsa and Seòras; Irish Gaelic Seoirse; Welsh Siôr, Siôrs and Siorus; and Cornish Jago.
There are several native or immigrant saints of England from the Anglo-Saxons to the late medieval period who have long been venerated in this country:
Alban - St Alban is regarded as the first British martyr (i.e. Britain's protomartyr). A Christian in 4th century Roman Britain, Alban's cult has been revered since the early Middle Ages. His name derives from the old Celtic word meaning both "white" and "world."
Audrey - St Etheldreda (d. 679), princess of East Anglia and later Queen consort of Northumberland. She became abbess of Ely in Norfolk and has been revered there since the early Middle Ages. Her original Saxon name was Æþelðryþe (Æthelthryth) meaning "noble strength." Etheldreda was the Latinised variant while Audrey became the medieval vernacular form.
Augustine - St Augustine (d. 604) was the first Archbishop of Canterbury, a Confessor, and regarded as "Apostle of the English." The name Augustine is a Roman one meaning "belonging to Augustus," which itself means "majestic, pious, venerable." The medieval English form of Augustine was Austin.
Bede - The Venerable Bede (d. 735) was a scholar and historian, made Doctor of the Church by Pope Leo XIII. It is thought his name derives from the Anglo-Saxon bed "prayer."
Chad - St Chad (d. 672) was Bishop of the Northumbrians and Bishop of the Mercians, credited with with converting the Mercians with his brother St Cedd. His name most likely derives from the Celtic element cad "battle."
Cuthbert - St Cuthbert (d. 687), Bishop of Lindisfarne and sometimes called the "Wonderworker of Britain." He is was often regarded as the patron of northern England. Another St Cuthbert (d.760) was an Archbishop of Canterbury. His name is Old English, made up of the words cuþ "famous" and beorht "bright."
Dunstan - St Dunstan (d. 988), Archbishop of Canterbury, was a monk who became chief councillor to King Edmund the Magnificent. He is known for endeavouring to establish peace between the different peoples of England and raising standards of monastic life. His name is composed of the Old English elements dun "hill" and stan "stone."
Edith - St Edith of Wilton (d.984) was a daughter of King Edgar the Peaceable and St Wulfthrith. She was a contemporary and associate of St Dunstan who became Abbess of Wilton. Her Anglo-Saxon name was Eadgyð, derived from the elements ead "wealth, fortune" and gyð "war".
Edmund - St Edmund the Martyr (d. 869) was King of East Anglia. Before George, Edmund was regarded as Patron-Saint of England alongside Edward the Confessor. His Old English name, Eadmund derives from ead "wealth, fortune" and mund "protection."
Edward - St Edward the Confessor (d 1066), King of England, was also once considered to be England's patron saint alongside St Edmund. There is also St Edward the Martyr (d.978) who was also a King of England. Eadward in Old English derives from ead "wealth, fortune" and weard "guard."
Felix - St. Felix of Dunwich (d. 647) was born in Burgundy who travelled to England as a missionary. He became the first bishop of the East Angles and set up a school to help boys learn how to read. Felix is a Latin name meaning "happy, favourable, fortunate."
Frideswide - St Frideswide (d.727) was a princess of Mercia who became Abbess in Oxford. She is often considered a patron there. Her original Old English name was Friðuswīþ (Frithuswith), composed of the elements frið "peace, tranquilty, security, refuge," and swið "strong, mighty, powerful."
Hugh - St. Hugh of Avalon (1140-1200), was a bishop of Lincoln. He was a French nobleman who came to England to be prior of the first Carthusian house in England. He is known for his charitable works and is now regarded as the patron saint of sick children, sick people, shoemakers and swans. Hugh is a French form of the Germanic Hugi meaning "heart."
Julian - St Julian of Norwich (d.1416) was one of the most important English anchoresses. No one knows her real name -- St Julian was the name of the church in which she sequestered herself. She has never been officially canonised but she was regarded as a saint in Norfolk for centuries. Julian was not uncommon as a given name for girls named in her honour.
Osmund - St Osmund (d.1099) was a Norman nobleman who came to England with, and was advisor to, William the Conqueror. He later became Bishop of Salisbury. In Old English the name derives from os "God" and mund "protection."
Oswald - There are two notable English saints to bear this name: St Oswald (d. 642), King of Northumbria, and St Oswald (d.992), Archbishop of York. His Old English name, Osweald, is made from os "God" and weald "power."
Swithin - St Swithin (d. 862). or Swithun, was Bishop of Winchester known for many posthumous miracles. Tradition has it that whatever the weather is on St Swithin's Day (15th July), it will continue for forty days. His name derives from the Old English word swiþ "strong."
Theodore - St Theodore (d.690), was born in Tarsus and saint by the Pope to England to become Archbishop of Canterbury. He is known for having promoted learning, establishing several seminaries. Theodore is the English form of the Greek Theodoros meaning "gift of God."
Wilfrid - St Wilfrid (d.709) was Bishop of York and several other places and is regarded as one of England's greatest saints. He converted Sussex, the last pagan part of Britain, to Christianity and set up monastries in Northumbria, Mercia, Sussex and the Isle of Wight. His name derives from wil "will, determination" and frið "peace".
Wulfstan - St Wulfstan (d.1095), also known as Wolstan, was Bishop of Worcester, was the last surviving pre-Conquest bishop. It is said that Henry II and Eleanor of Aquitaine visited Worcester Cathedral and placed their crowns on the shrine of Wulfstan. His name was composed of the Old English elements wulf "wolf" and stan "stone."