Lord Valentine's Castle
This book can be downloaded and read in iBooks on your Mac or iOS device.
Set in an immense world teeming with alien races and fantastic, almost magical, machinery, Valentine, an itinerant juggler, wakes up one morning with only a vague and troubled idea of who he is. He gradually discovers, through dreams and portents, that he is in fact his namesake: Lord Valentine, the Coronal, his body and throne stolen by a usurper.
Across the giant world of Majipoor, Valentine sets out on a quest to win back his throne - and discover which of his enemies has the power to vanquish him so utterly from not just his throne, but his very life . . .
(First published 1980)