The Excalibur problem is that, over time, people have combined two different Arthurian swords into a single blade. This is a serious pet-peeve of mine.
Sword # 1: "Clarent", the sword in the stone. It was used in Ceremonies (e.g. the dubbing of knights). This sword designates Arthur as being rightful heir of Uthur.
Sword # 2: "Excalibur/Caliburn", given to ...
This may be "Once and Future" by the late Terry Pratchett, first published in Camelot in 1995. A time-travelling historian named "Mervin" gets stranded in an anachronism stew that mostly matches Arthurian legend, and he reproduces the sword-in-a-stone bit in order to get a king who will follow his advice for advancing technology.
All the mechanical ways ...
Singing Camelot Knight #4
Who was played by John Cleese (who also played Sir Lancelot the Brave).
You can see yellow and silver in this frame:
This knight is also wearing yellow and silver, and the crest is conceivably the same:
And in case you are not quite sure who's face that is, here is John Cleese wear the same pattern and crest:
So yes, a knight ...
The short version is that both of those swords are Excalibur. Le Morte D'Artur is, to be blunt, incredibly self-contradictory in places. Malory took a number of existing stories and collected them without always concerning himself with conflicts between them.
In Robert de Boron's Merlin, Arthur obtained the throne by pulling a sword from ...
It's been a long time since I read them, but I believe Merlin used a lodestone (magnet, but not electromagnet) in this way in A. A. Attanasio's The Dragon and the Unicorn series. Sadly I can't find a ready summary now.
It is very likely he actually went back or at least had contact with someone in Camelot, as by the next scene the following is stated (Gwen's coronation, transcript from wikia):
LEON: The King is dead. [Gaius and Gwen share a glance. Gwen looks
back at Leon.]
LEON: Long live the Queen!
While enough people knew Arthur was in a bad shape after the ...
Sounds like Maleger; from Brewer's dictionary:
Captain of the rabble rout which attack the castle of Temperance. He was “thin as a rake,” and cold as a serpent. Prince Arthur attacks him and flings him to the ground, but Maleger springs up with renewed vigour. Arthur now stabs him through and through, but it is like stabbing a shadow; he then takes him in ...
It also showed up in Interstellar Patrol II the Federation of Humanity, by Christopher Anvil. It wasn't a time-travel story, but there was absolutely a sword in a stone that was being used to determine a ruler, and people mucking about with magnets to mess with the situation.
The Celtic-Mythology/Arthurian-Legends theme is very visible in Lady of the Lake, but it's seen throughout the saga.
The Tor Zireael is very similar to the seat of the Fisher King as described by de Troyes in Percival... And it's mentioned in The Time of Contempt. In this book we start to see more clearly who really is Ciri (Cirilla = Zireael, by ...
I'm pretty sure that Arthuric references appear only in the last book.
As Ciri travelled to what seems to be another world, it's not strange that these references are exclusive to this book, as previously we didn't seen anything about it.
IMHO the way in wich Ciri jumped between worlds and how it's longer presence in this kind or Arthurical Europe started ...
This may be the Magic Tree House Series.
Read this in the early 90s but was probably from the 70s or 80s.
This series began being published in 1992
The setting was Celtic or Arthurian.
It involved transportation between the real world and the magical word.
The books dealt with magical portals and time travel - including, but not ...
I can't find much about it online, but the Dyason series by Warren James Palmer has similar elements.
Summary of the first book, Empire of the minds (1995), from Amazon:
By the year 2045 the United Nations World Defence Force can finally guarantee the security of every nation on the planet through the use of orbital laser battle stations.
That is until ...
Could this be Camelot (1998) as part of the Enchated Tales series? I can only find the odd clip of it online, however, there is this clip where the knights put their swords on the table, they get enchanted and they then all thrust them into the air.
There is also this longer montage clip:
Could it be The Weirdstone of Brisingamen by Alan Garner?
It is not explicitly Arthurian but it has a character identified as the Morrigan and a wizard called Cadellin Silverbrow that I always think of as more or less equating to Merlin.
The main charcters are a brother and sister whose parents are overseas. It somewhat matches your other details and there ...
Sounds quite like Susan Cooper's excellent The Dark Is Rising sequence. Most of the details match, especially for the fourth and fifth books, except that the protagonists weren't orphans or siblings.
There was an unsuccessful film of the second book.
It's 330 pages instead of 60, and the illustrations don't look like pencil to me, but your description instantly reminded me of Roger Lancelyn Green's King Arthur and His Knights of the Round Table. Portions of the book can be read on Google Books; does this look like the kind of illustrations you remember?
It could be "King Arthur & the Knights of the Round Table" ("Entaku no Kishi Monogatari Moero Āsā"), another anime series (very loosely) based on the Arthurian legends.
It originally aired in 1979 in Japan, and dubbed versions were broadcasted in the following years in many countries, which fits your timeline.
The first cartoon that popped into my head was an Oz series from the late sixties/ early seventies that was aired in the UK a few times in the eighties.
Arthur! and the Square Knights of the Round Table
Could it possibly be The Legend of Prince Valiant? It came out at the beginning of 1990 and it centers around Camelot, although the story is technically about Prince Valiant.
In my own searches I seem to have confused one series with the other, so I gave this suggestion in case it could be the answer.