From Bäcklund to Darboux, this monograph presents a comprehensive
journey through the transformation theory of constrained Willmore
surfaces, a topic of great importance in modern differential geometry
and, in particular, in the field of integrable systems in Riemannian
geometry. The first book on this topic, it discusses in detail a
spectral deformation, Bäcklund transformations and Darboux
transformations, and proves that all these transformations preserve the
existence of a conserved quantity, defining, in particular,
transformations within the class of constant mean curvature surfaces in
3-dimensional space-forms, with, furthermore, preservation of both the
space-form and the mean curvature, and bridging the gap between
different approaches to the subject, classical and modern. Clearly
written with extensive references, chapter introductions and
self-contained accounts of the core topics, it is suitable for newcomers
to the theory of constrained Wilmore surfaces. Many detailed
computations and new results unavailable elsewhere in the literature
make it also an appealing reference for experts.