Gisela, daughter of Charlemagne
Gisela, (in or before 781 - 808 or later) was a daughter of Charlemagne from his marriage to Hildegard.
She was baptized at the Basilica of Sant'Ambrogio in 781 by Thomas, Archbishop of Milan.
She was educated at the castle in Aachen, with Alcuin who gave her the nickname "Delia".
According to Alcuin she took a particular interest in astronomy.
Alcuin refers to "Delia" in some of his poetry.
Like her sisters Bertha and Rotrude, Gisela never married.
Sources vary regarding her later life, some sources state 808 as a death date, others state that in 814 she was sent to a convent by her brother Louis the Pious.
Charlemagne
Charlemagne  or Charles the Great (2 April 748 – 28 January 814), numbered Charles I, was King of the Franks from 768, King of the Lombards from 774, and Emperor of the Romans from 800.
During the Early Middle Ages, he united the majority of western and central Europe.
He was the first recognised emperor to rule from western Europe since the fall of the Western Roman Empire three centuries earlier.
The expanded Frankish state that Charlemagne founded is called the Carolingian Empire.
He was later canonized by Antipope Paschal III.
Charlemagne was the eldest son of Pepin the Short and Bertrada of Laon, born before their canonical marriage.
He became king in 768 following his father's death, initially as co-ruler with his brother Carloman I. Carloman's sudden death in December 771 under unexplained circumstances left Charlemagne the sole ruler of the Frankish Kingdom.
He continued his father's policy towards the papacy and became its protector, removing the Lombards from power in northern Italy and leading an incursion into Muslim Spain.
He campaigned against the Saxons to his east, Christianizing them upon penalty of death and leading to events such as the Massacre of Verden.
He reached the height of his power in 800 when he was crowned "Emperor of the Romans" by Pope Leo III on Christmas Day at Rome's Old St. Peter's Basilica.
Charlemagne has been called the "Father of EuropePater Europae"), as he united most of Western Europe for the first time since the classical era of the Roman Empire and united parts of Europe that had never been under Frankish or Roman rule.
His rule spurred the Carolingian Renaissance, a period of energetic cultural and intellectual activity within the Western Church.
Emperors of the Holy Roman Empire considered themselves successors of Charlemagne, as did the French and German monarchs.
The Eastern Orthodox Church viewed Charlemagne less favorably due to his support of the filioque and the Pope's having preferred him as Emperor over the Byzantine Empire's Irene of Athens.
These and other disputes led to the eventual split of Rome and Constantinople in the Great Schism of 1054.
Charlemagne died in 814 and was laid to rest in his imperial capital city of Aachen.
He married at least four times and had three legitimate sons who lived to adulthood, but only the youngest of them, Louis the Pious, survived to succeed him.
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Question: Who is the paternal grandfather of Gisela, Daughter Of Charlemagne?
Answer: Pepin the Short