YA or childs, dates from 70s, kids travel in time via a magic coin, at least one scene with knights and jousting

[Woodge]

Read this ages ago, early 70s. I remember a taunt in the book rhyming girl and churl. There may be a knight character named Roland.

[Sirvantes]

Half Magic, by Edward Eager? There is the coin, and a tournament of knights, and even the word 'churl', but no Roland.

[Woodge]

Wow! It could be that! Or possibly "Knight's Castle" by the same author. As I read the descriptions, the character name of Roger rang a bell. Thanks!

[Sirvantes]

Glad we could help. One of my favorites as a child, by the way.

[STU]

The Magic Coin
The Magic Coin by Ruth Chew?
Can't remember enough of the plot to know if there were knights in it, but pretty sure it involved travelling via magic coin

[Kris]

Sirvantes' suggestions: Half Magic (1954) or Knight's Castle (1956) by Edward Eager - The word "churl(s)" appears in both books.

STU's suggestion: The Magic Coin (1983) by Ruth Chew

[Michele]

This is almost certainly Half Magic by Edward Eager -- loved this as a kid and still do. One of the children, a girl named Katherine, dubs herself "Sir Kath" and jousts against Lancelot :)

[Kris]

Google Books preview of Half Magic by Edward Eager - Sirvantes and Michele's suggestion:

https://books.google.com/books?id=PsN...

Quotes from the book:
- Description: It all begins with a strange coin on a sun-warmed sidewalk. (...) It turns out the coin grants wishes - but only by half, so that you must wish for twice as much as you want.
- ... Flee, churls. Avaunt and quit my sight, thy bones are marrowless. Giddy-up." Sir Launcelot chirruped to his horse, and the lady chirruped to hers, and away they went, galloping down the King's Highway. The four children had to scatter ...

[Daisy]

In the unlikely case it isn't Half Magic, it could possibly be Five Children and It. It's not an exact match, but does have a medieval siege scene and disappearing coins.

[Heather]

Again not an exact match, but what about The Queens Nose by Dick King Smith. A girls uncle returns from India and gives her a mysterious coin, she finds that magical things happen whenever she rubs the queen's face on the coin

[Lobstergirl, au gratin]

Woodge, did you confirm this was Half Magic?