Question: What Northumbrian missionary saint studied at Rath Melsigi?

full_context: Document 1: Kings of the Angles: The Angles were a dominant Germanic tribe in the Anglo-Saxon settlement of Britain, and gave their name to the English, England and to the region of East Anglia. Originally from Angeln, present-day Schleswig-Holstein, a legendary list of their kings has been preserved in the heroic poems "Widsith" and "Beowulf", and the "Anglo-Saxon Chronicle".
Document 2: Hiberno-Scottish mission: The Hiberno-Scottish mission was a series of missions and expeditions initiated by various Irish clerics and cleric-scholars who, for the most part, are not known to have acted in concert. There was no overall coordinated mission, but there were nevertheless sporadic missions initiated by Gaelic monks from Ireland and the western coast of modern-day Scotland, which contributed to the spread of Christianity and established monasteries in Britain and continental Europe during the Middle Ages. The earliest recorded Irish mission can be dated to 563 with the foundation of Iona by the Irish monk Saint Columba. Columba is said by Bede and Adamnán to have ministered to the Gaels of Dál Riada and converted the northern Pictish kingdoms. Over the next centuries more missions followed and spread through Anglo-Saxon England and the Frankish Empire. The early missions are often associated with the Christian practice known as Celtic Christianity, which was distinguished by its organizations around monasteries rather than dioceses and certain idiosyncratic traditions, but the desire to maintain a relationship with the Holy See saw their missions take on a more Roman character.
Document 3: Frithwald: Frithwald (Old English: "Friþuweald" or "Friðewald"; d. 762 × 764) was an Anglo-Saxon Bishop of Whithorn. The version of the "Anglo-Saxon Chronicle" in the "Worcester Chronicle" says that in 735 he succeeded Pehthelm, after the latter's death, as Bishop of Whithorn. The only other source for Frithwald is the entry in versions D and E of the "Anglo-Saxon Chronicle" which, "sub anno" 762, relate that:Frithwald, bishop at Whithorn, died on the Nones of May [May 7]. He was consecrated at Chester on the eighteenth before the Kalends of September [August 15], in the sixth winter of Ceolwulf's kingship [734/5]; and he was bishop twenty-nine winters<br>"Friþuweald biscop æt Hwiterne forðferde on Nonas Maius, se wæs gehalgod on Ceastre on .xviii. Kalendas September þam .vi. wintra Ceolwulfes rices, 7 he wæs biscop .xxix. wintra". If the Worcester source is correct, that would put his death in 764; the entry is also sometimes thought to cover the year 763.
Document 4: Æthelstan Half-King: Æthelstan (fl. 932 - 956), was an important and influential Ealdorman of East Anglia who interacted with five kings of England, including his adopted son Edgar the Peaceful. Many of Æthelstan's close relatives were also involved in important affairs, but soon after the death of king Eadred in 955, he left his position and became a monk at Glastonbury Abbey.
Document 5: Paulinus of York: Paulinus (died 10 October 644) was a Roman missionary and the first Bishop of York. A member of the Gregorian mission sent in 601 by Pope Gregory I to Christianize the Anglo-Saxons from their native Anglo-Saxon paganism, Paulinus arrived in England by 604 with the second missionary group. Little is known of Paulinus' activities in the following two decades.
Document 6: History of schools in Scotland: The history of schools in Scotland includes the development of all schools as institutions and buildings in Scotland, from the early Middle Ages to the present day. From the early Middle Ages there were bardic schools, that trained individuals in the poetic and musical arts. Monasteries served as major repositories of knowledge and education, often running schools. In the High Middle Ages, new sources of education arose including choir and grammar schools designed to train priests. Benedictine and Augustinian foundations probably had charitable almonry schools to educate young boys, who might enter the priesthood. Some abbeys opened their doors to teach the sons of gentlemen. By the end of the Middle Ages, grammar schools could be found in all the main burghs and some small towns. In rural areas there were petty or reading schools that provided an elementary education. Private tuition in the families of lords and wealthy burghers sometimes developed into "household schools". Girls of noble families were taught in nunneries and by the end of the fifteenth century Edinburgh also had schools for girls, sometimes described as "sewing schools". There is documentary evidence for about 100 schools of these different kinds before the Reformation. The growing humanist-inspired emphasis on education cumulated with the passing of the Education Act 1496.
Document 7: Wimund: Wimund was a bishop who became a seafaring warlord adventurer in the years after 1147. His story is passed down to us by 12th-century English historian William of Newburgh in his "Historia rerum anglicarum", Book I, Chapter 24 entitled "Of bishop Wimund, his life unbecoming a bishop, and how he was deprived of his sight".
Document 8: Adalbert of Egmond: Saint Adalbert of Egmond (also called Adelbert of Egmond) (died c. 710 in Egmond) was a Northumbrian Anglo-Saxon missionary. He was one of Saint Willibrord's companions in preaching the gospel in Holland and Frisia.
Document 9: Saint Boniface: Saint Boniface (Latin: "Bonifatius" ; 675 – 5 June 754 AD), born Winfrid, Wynfrith, or Wynfryth in the kingdom of Wessex in Anglo-Saxon England, was a leading figure in the Anglo-Saxon mission to the Germanic parts of the Frankish Empire during the 8th century. He established the first organized Christianity in many parts of Germania. He is the patron saint of Germania, the first archbishop of Mainz and the "Apostle of the Germans". He was killed in Frisia in 754, along with 52 others. His remains were returned to Fulda, where they rest in a sarcophagus which became a site of pilgrimage. Facts about Boniface's life and death as well as his work became widely known, since there is a wealth of material available—a number of "vitae", especially the near-contemporary "Vita Bonifatii auctore Willibaldi", and legal documents, possibly some sermons, and above all his correspondence.
Document 10: History of Herefordshire: The History of Herefordshire starts with a shire in the time of Athelstan (895–939), and Herefordshire is mentioned in the "Anglo-Saxon Chronicle" in 1051. The first Anglo-Saxon settlers, the Magonsætan, were a sub-tribal unit of the Hwicce who occupied the Severn valley. The Magonsætan were said to be in the intervening lands between the Rivers Wye and Severn. The undulating hills of marl clay were surrounded by the Welsh mountains to the west; the Malvern Hills to the east; the Clent Hills of the Shropshire borders to the north, and the indeterminate extent of the Forest of Dean to the south. The shire name first recorded in the "Anglo-Saxon Chronicle" was derived from "Here-ford", Old English for "Army crossing", the location for the city. The area was covered first by Offa of Mercia, who constructed the dyke as a boundary to keep warring tribes out of the Mercian kingdom: an early indication of the ambivalent relations with the Welsh. The shire as an administrative unit was developed from Alfred the Great's Burghal Hidage, and the Shire-reeve courts of the Hundred. King Edgar the Ætheling was a regular visitor, and founded the diocese, previously part of the see of Worcester, in 976. The establishment of a centre of law and justice was supported by a monastic chapter that flourished during the Tenth century Reformation. Hereford's geographical location at the hub of the shire allowed Anglo-Saxon ealdormen to manage affairs; and Hereford played a vital role in the Scandinavian wars until Ralph, Earl Hereford was deposed by the regal Earl Harold Godwinson.
Document 11: Anglo-Saxon mission: Anglo-Saxon missionaries were instrumental in the spread of Christianity in the Frankish Empire during the 8th century, continuing the work of Hiberno-Scottish missionaries which had been spreading Celtic Christianity across the Frankish Empire as well as in Scotland and Anglo-Saxon England itself during the 6th century (see Anglo-Saxon Christianity).
Document 12: Saint Patrick: Saint Patrick (Latin: "Patricius" ; Irish: "Pádraig" ] ; Welsh: "Padrig" ) was a fifth-century Romano-British Christian missionary and bishop in Ireland. Known as the "Apostle of Ireland", he is the primary patron saint of Ireland, along with saints Brigit of Kildare and Columba. He is also venerated in the Anglican Communion, the Old Catholic Church and in the Eastern Orthodox Church as equal-to-the-apostles and "Enlightener of Ireland".
Document 13: Rath Melsigi: Rath Melsigi the monastery in Ireland during the 7th century where Saint Egelbert, an Anglo Saxon was educated. Many Anglo Saxons and Frankish were educated at Irish monasteries, including King Alfred of England, Oswald of England & Dagobert II of France, to name a few. It was located in what is now the townland of Clonmelsh, County Carlow. Among those known to have studied there were Willibrord, Swithbert, and Egbert (639-729), who organised the mission to Frisia. Others of the English community at Rath Melsigi included Adalbert of Egmond, Botolph and Chad of Mercia. Others studied at Irish monasteries at Armagh, Kildare, Glendalough, and Clonmacnoise.
Document 14: Saint Ninian: Saint Ninian is a Christian saint first mentioned in the 8th century as being an early missionary among the Pictish peoples of what is now Scotland. For this reason he is known as the Apostle to the Southern Picts, and there are numerous dedications to him in those parts of Scotland with a Pictish heritage, throughout the Scottish Lowlands, and in parts of Northern England with a Northumbrian heritage. In Scotland, Ninian is also known as Ringan, and as Trynnian in Northern England.
Document 15: Willibrord: Willibrord (Latin: "Villibrordus" ; 658 – 7 November AD 739) was a Northumbrian missionary saint, known as the "Apostle to the Frisians" in the modern Netherlands. He became the first Bishop of Utrecht and died at Echternach, Luxembourg.
ground_truth: Willibrord