  We have studied the gamma d ---> Delta++ Delta- reaction which requires the
collaboration of the two nucleons in deuteron. By means of a model previously
developed for the gamma p ----> p pi+ pi- reaction, the two body exchange
currents leading to double delta creation are derived. A fair agreement is
obtained with a recent experiment, but more precise measurements and the
extension to higher photon energies look advisable in order to see the limits
of the present theoretical approach
