The paleographical and codicological analysis of a valuable Greek manuscript, Vindob. phil. gr. 31, with Euclid’s Elementa, Optica and Phaenomena, establishes that seven scribes collaborated in its copy at the end of the eleventh or beginning of the twelfth century and that their work is linked to the different models of Euclid they used both for the text and for the commentary. Several later hands added notes to the text, noticeably Maximos Planudes, whose handwriting we identify in the autographic addition on the upper margin of f. 144v (sch. Elem. X.223).