A unique Late Antique Crossbow Fibula stolen from Turin which, due to its two inscriptions can be dated precisely to AD 306-7:
CONSTANTINE CAES VIVAS and HERCULI CAES VIVAS
Length 8 cm
Source: Carabinieri Database Codice Bene: 11565[3] / Nr. Bollettino 8
Published:
Barbara Deppert-Lippitz, A Late Antique Crossbow Fibula in the
Metropolitan Museum of Art, Met Bulletin, pp. 49ff, figure 10. Link http://www.metmuseum.org/pubs/