Tetralogie

Tetralogy is a term used to describe a set of four works that are linked by a common story, theme, or set of characters. It can apply to literature, film, theatre, and other narrative arts. A tetralogy may present a single overarching narrative divided into four installments, or four distinct but related stories that together form a coherent whole. The four parts are typically intended to be read or viewed as a continuous arc, with each installment contributing to the development of themes and characters.

Etymology and usage vary by language. The term derives from the Greek tetra- meaning four and -logy meaning discourse or study. In English, it is commonly written as tetralogy. In other languages, forms such as tétalogue, Tetralogie, or tetralogia may be used. The concept is not strictly codified; some long-running series are retrospectively described as tetralogies when a four-part structure emerges as the complete set.

Notable examples include Wagner's Ring Cycle (Der Ring des Nibelungen), a quartet of operas designed as a single continuous epic: Das Rheingold, Die Walküre, Siegfried, and Götterdämmerung. In contemporary fiction, a four-volume series such as Christopher Paolini's The Inheritance Cycle (Eragon, Eldest, Brisingr, Inheritance) is widely recognized as a tetralogy. The term emphasizes unity of narrative across four parts and is used to distinguish such sequences from trilogies or longer multi-volume sagas.