We study the phase diagram of the three-dimensional classical ferromagnetic Heisenberg
model with an easy-plane crystalline anisotropy and an easy-axis exchange anisotropy
through Monte Carlo simulations. We employ the Metropolis algorithm together with single-
histogram techniques in order to characterize the transitions in each region of the phase
diagram. Our results reveal, besides the disordered phase, the existence of Ising-like and
XY-like ordered phases which are separated by a first-order transition line.