The Architrenius is a Latin allegorical poem in hexameters, dedicated to Walter of Coutances, Archbishop of Rouen, in 1184. Little is know about its author, Johannes de Hauvilla: he was probably originary from the village of Hauville, near Rouen; at the time of the dedication of Architrenius, he was presumably alread a teacher of the cathedral school of Rouen.

The poem is divided in nine books. It narrates the allegorical journey of the protagonist, a young man called Architrenius (from Greek, 'Arch-mourner'), in search of the goddess Nature.

Architrenius: starts on f. 78r. It is introduced by the rubricated words Incipit liber magistri iohannis havillensis qui architrenius dicitur ad gualterum de constantiis rotomagensem archiepiscopum. The text begins with Velificatur athol dubio mare ponte ligatus.

Book 1: f. 78r.

Book 2: f. 80v.

Book 3: f. 83r.

Book 4: f. 87v.

[A folio has fallen between 87 and 88. The last line of book 4 (v. 483) and the beginning of book 5 (up to v. 187) are therefore missing].

Book 5: f. 88r (from v. 188).

Book 6: f. 89v.

Book 7: f. 92r.

Book 8: f. 94v.

Book 9: f. 97r.

It ends on f. 99v with the words populis dilectus et ultra. Explicit.

Prologue: on f. 99v. It is introduced by the rubricated words Incipit prologus in librum magistri (then in blue) iohannis de hauvilla qui architrenius (red again) dicitur ad gauterum rothomagensem archiepiscopum. It begins with the words Architrenius quidam cum ad annos virilis roboris devenisset.

There is a very fine initial at the beginning (f. 78r), in which is a small miniature on a punctured gold ground, representing, in the upper part, Xerxes sailing over Mount Athos, and below, Xerxes crossing the Hellespont.