Not a full list by any means list.
Taken from notes made over many years of research in the writing of "This Mighty Isle".
These listed, are the ones that raised my imagination.
Proper recognition to authors and book titles given at end,but Not in any order or detail.
My thanks to all these Authors.

Constantine the Great,306ce,Proclaimed Empera at York [Eboracum]Gave freedom for Christians to worship 313ce.

"Cathbaid"Druid GrandFather of CúChlain.

"Cader Idris"a stone seat,perfect chair in Caer Sidi (Revolving Castle)

"Columcille",known before "Crimthan" the Wolf.

Columcile: Hallowed Burial. " Heaven is not how it is portrayed.

"Hell is not how it is portrayed"

" The saved are not always content"

" The lost canst find a return"

His companion "Oran"a Druid.Oran buried alive to sanctify the first church.After three days unburried.uttering "Death is not a wonder,and hell is not as it is described""Earth on Oran's eyes lest he blabs further" Columcille."Aidan"his successor swore on the "Black Stone of Iona. "Mo Drui Mac Dé"My Druid,My God".

Ceriddwen-First born name "Movrah" [Raven of the Sea] Devine Sow,"Henwen"White Ancient,Grain Goddess.

"Claudia Rufina" [Child of Blue]A relation of "Linus"Who Succeeded St Peter as Head of the Early Church.

"Cessair" Granddaughter of Noah,Daughter of Bith,Noah's son.No room in the Ark,she was sent to the western borders of the world,were no sin was.

"Cesar" Enchantment against the Badb.He burned Sigils and Ogham signs into the turf.These he painted Blue with the Woadand Red with the Goats blood and white with Chalk.He lit ninecandles whilst enchanting the dead language Crom Cruach understands, as green light became the spectres a wraith swept from the sky.

Crom Cruach-The Bent or Bowing One of the mound,on the plains of Slecht.

"Caladcolg"- Best blade in Ireland.

"Calan Mai" Beltaine.

"Celtic" [Keltoi] Stranger.

"Cuhelyn"- a Bard of the sixth Century.

"Circle"-Kirkos- Greek word for Circle.

"Catigern"British chief who died fighting Saxons at Aylsford 5ce.

Celtic Oath-Fiannan- Bodyguard swore to stand firm."Though the Earth Should Split Under Us and the Sky above on us".

"Creirwry"[Dear One]Daughter of Ceriddwen.

"Creiddylad" May Queen,Daughter of the Sea God Llyr.

"Chastiefol"Sword of Arthur.

"Caledfwlch"Another of Arthur's swords.

"Courechouse" Sword of King Ban[Brother to King Bors of Gaul]

"Ceugant"- The realm of Purest Light.

"Catus Decianus" executed Simon the Zealot at Caister.

"Crom Deroil" Druid of Ulster.

"Christmas Day" Was not celabrated on 25th Dec until the year 353ce,declared by pope" Liberius".

Book of Druidry(Ross Nichols)Mythology of the British Isles(Geoffrey Ashe)Ancient Faith of Britain(Dudley Wright)Druid Way(P Carr-Gom)Druid Renaissance(P Carr-Gom)The Encyclopedia of Celtic Wisdom(Caitlin and John Matthews)Glastonbury,Avalon off the heart(Dion Fortune)The White Goddess(Robert Graves)Druidry(Philip Shallcrass)Avalonian Quest(Geoffrey Ashe)Druid Animal Oracle(Philip and Stephanie Carr-Gom)Arthurian Myth and Legend(Mike Dixon-Kennedy)The Voice Within the Wind(Greywind) The Druid Sourse Book(John Matthews)Gods of the Celts(Miranda Green)The Lore of the Bard(Arthur Rowen)The Celtic Year Book(John King)Pagan Pathways(Emma Restall-Orr)Act of God(Philips)Bloodline of the Holy Grail(Laurence Gardner)Dead Sea Scrolls Deception(Richard Leighand Michael Baigent)Magi(G Ash)Witches,Druids and King Arthur(Ronald Hutton)Living Druidry(Emma Restall-Orr)The mystical Qabalah(Dion Fortune)Secrets of the Druids(John Matthews)