Lewis was not new to writing, and I'm sure he purposely crafted PC in this way. He told stories and that was the purpose of his books. Look at VDT. Non-typical book layout, but an extremely successful, selling book.

I thought it was a great idea to have Caspian's/ Trumpkin's story told in flashback form. Sometimes when reading stories with multiple story lines, I get lost in the characters' adventures and sometimes have to reread to understand a chapter better.

I agree with Louloudi that reading books where you skip from character to character with each chapter change can be confusing. On the other hand, I can't think of all that many books off the top of my head that use a structure similar to Prince Caspian.

I've heard it said that with the massive flashback readers have to reinvest in an entirely new set of characters but it's never really bothered me. That's just the way PC works.

I can't think of all that many books off the top of my head that use a structure similar to Prince Caspian.

Perhaps you might say that The Lord of the Rings uses some of the same elements - there are different groups of characters which we follow for several chapters before jumping back to whatever a different group was doing at the same time. There isn't the same major single flashback, though.

I think flashbacks are fine, when they are long enough that you have time to get immersed in them before you are taken back to the present again. Reinvesting in new sets of characters is fine, too - if there are lots of characters, you have to invest in all of them anyway

When there are several groups of characters doing things seperately from each other, some solution will have to be found for how to move between them. Only one chapter for each before we go to someone else, might show more clearly the timeline and how the events are related to each other, but it can get very fragmented. Several chapters for one group before changing, as is mostly the case here, gives you time to get immersed in each section - but at the cost of a clear view of the connection between the timelines. Perhaps that's why this structure isn't seen as often.

I think the book of PC is structured the way it is, because when Lewis wrote it there was only one book about Narnia out there, and no films, TV series or (as far as I'm aware) radio series; so the whole notion of Narnia (as a place) was still new to everyone. Therefore he had to start by focussing on the Pevensies as they were the only characters in the new story whom everyone who'd read the first book would know. It would have been more confusing to readers to have had chapter after chapter about a whole new set of people with no explanation (as yet) as to why we were reading their story.

When he wrote The Last Battle, Narnia was much more familiar both to the fans of the series and the world at large, so he didn't need to start with Eustace, Jill and the other Friends of Narnia. Readers would have been more ready to accept new characters at the beginning, and if anything be wondering whether we would finally see anyone from our world in the story or whether it would turn out to be "self-contained" within the Narnian world like The Horse And His Boy.

When Walden made the film of PC, again, the idea of Narnia was more familiar to people generally than it was when the book was first published, so it was feasible (feel free to disagree!) to start with Caspian's plight and then switch to the Pevensies in London. Although I don't remember there being much explanation as to why Caspian was so pro-Old Narnia in the film, as it didn't show him growing up and being told stories about it by his nurse.

I was thinking about this the other day, and I realized that there are a number of old legends and epics that work this way: introducing a character and then going into the whys and wherefores of his inclusion and backstory. I think that this was likely what Lewis was working from, since he loved old legends and stories.