So many books I love already mentioned... will add a few that haven't been so far.
Children first......
Ask Me No Questions - Ann Schlee. Set during the1848 cholera epidemic, thoughtful and sad [age 11 +].
The Moon in the Cloud - Rosemary Harris(+ 2 sequels). Noah's Ark, talking cats, the royal courts of Egypt- I couldn't stop reading this, at the age of 45! [for age 9/10 upwards].
The Mantlemass series by Barbara Willard. I love love love these books which again I read as an adult. Seven main books plus two outliers [Miller's Boy much simpler, Keys of Mm fill-in short stories]. Start with The Lark and the Laurel in 1485 and go through to the mid 1600s with interconnected familes in the Ashdown Forest. Beautifully written and haunting. For young teens upwards.
Mail-Order Wings by Beatrice Gormley. Nine-year old Andrea orders wings from a magazine and they work! Great fun. 8 / 9up
The Dancing Bear by Peter Dickinson. ' A Greek slave, his dancing bear, and an old holy man journey from Byzantium to rescue the slave's young mistress from the Huns.' 10 up?
My daughter loved Topsy and Tim, the Drina ballet books by Jean Estoril, Snowfall by KM Peyton [Victorian girl climber], and Kiss The Dust by Elizabet Laird [Kurdish children escaping persecution].
My son loved Willard Price, Jennings, Antonia Forest, and My Father's Dragon by Ruth Stiles Gannett, which surprise surprise is all about my father's dragon who has to be rescued from some very nasty wild animals by my father. [ 5-8 ].