ABSTRACT
In this chapter we recall a construction and basic properties of the main character of the remaining part of the book, the quintic del Pezzo threefold V5. This is a rational smooth Fano threefold with many remarkable features. It was studied from various points of view, including its biregular properties (see, e. g., [86] and [47]), birational maps (see, e. g., [66, §4.3]), Ka¨hler-Einstein metrics (see [22]), exceptional collections (see [91]), instanton bundles (see [110]) and others.
