An Etymological Dictionary of the German Language/Roche
Roche (1.), m., ‘ray, thornback,’ from LG. ruche; comp. the equiv. Du. roch, rog, AS. reohha, *rohha, whence MidE. reihe, rouhe; also E. roach, rocke? (E. ray is derived from Lat. raja, whence also Ital. raja, Fr. raie).
Roche (2.), m., ‘castle’ (at chess), from the equiv. MidHG. roch, n.; borrowed with chess-playing from the Fr. (roc, whence also MidE. and E. rook). The ultimate source is Pers. rukh, rokh, ‘archer mounted on an elephant’ (at chess), Deriv. rochieren.