... it must have been from the reigning French monarch that William the Conqueror took Henry for his youngest son, from whom the first Plantagenet King received and transmitted it to his ungracious son, his feeble grandson, and through him to the elder House of Lancaster, then to the younger, who for three generations wore it on the throne, and for whose sake it was revived in the House of Tudor.  Its right native shape is Harry; the other form is only an imitation of French spelling. (History of Christian Names, Yonge, 1884)

... Heinrich der Vogler (876) (Henry the Fowler), the husband of Matilda the Good, covered the name with glory; of such noble descent to begin with, and so adorned, what wonder that it speedily spread through the length and breadth of the land?
    Indeed the name hardly needed the added glory of saintship to urge its claims to popular favour amongst the nations of Western Europe.  Yet even this was granted it, for Henry the Fowler's son, Henry Duke of Bavaria, had also a son called Henry, who has since been canonized as a saint.
    Born in 972, the child was early placed under the care of St. Wolfgang, Bishop of Ratisbon, and from his earliest years gave promise of great intellectual strength and piety.  Henry succeeded his father as Duke of Bavaria in 1002, and was chosen Emperor upon the death of his cousin Otho III.  In the following year he was crowned King of Germany, and soon after his accession to the throne resigned his Duchy in favour of his brother-in-law Henry surnamed senior. 
    St. Henry did much towards fixing the canons of the church, and by his courage, prudence, and clemency was instrumental in quelling rebellion and enforcing justice. 
    In 1014 he went to Rome, where ten years after his election he was formally crowned Emperor by Pope Benedict VIII., amidst great pomp and rejoicing.
    Henry restored the sees of Hildesheim, Magdeburg, Strasburg and others, and endowed many churches and monasteries: he warred continually against paganism and barbarity, and made Poland, Bohemia, and Moravia tributaries of the Empire.
    Henry died after a reign of twenty-two years, in 1024, and was canonized in 1152.
    St. Henry of Treviso was a very different man.  Of humble parentage, his father's poverty deprived him of the means of education, and he began life as a day-labourer.  All his time that was not employed in an actual struggle for existence, he spent in acts of devotion, and leading a life of great privation he gave all he could to those poorer even than himself.  In Italy he is known as St. Rigo, the Italian diminutive of Arrigo or Henry. (Girls' Christian Names, Swan, 1905).