  Present-day massive galaxies are composed mostly of early-type objects. It is
unknown whether this was also the case at higher redshifts. In a hierarchical
assembling scenario the morphological content of the massive population is
expected to change with time from disk-like objects in the early Universe to
spheroid-like galaxies at present. In this paper we have probed this
theoretical expectation by compiling a large sample of massive
(M_{stellar}>10^{11} h_{70}^{-2} M_{Sun}$) galaxies in the redshift interval 0
< z < 3. Our sample of 1082 objects comprises 207 local galaxies selected from
SDSS plus 875 objects observed with the HST belonging to the POWIR/DEEP2 and
GNS surveys. 639 of our objects have spectroscopic redshifts. Our morphological
classification is performed as close as possible to the optical restframe
according to the photometric bands available in our observations both
quantitatively (using the Sersic index as a morphological proxy) and
qualitative (by visual inspection). Using both techniques we find an enormous
change on the dominant morphological class with cosmic time. The fraction of
early-type galaxies among the massive galaxy population has changed from
~20-30% at z~3 to ~70% at z=0. Early type galaxies have been the predominant
morphological class for massive galaxies since only z~1.
