  We report here initial but still strongly conclusive results on absolute ages
of galactic globular clusters (GGCs). This study is based on high precision
trigonometric parallaxes from the HIPPARCOS satellite coupled with accurate
metal abundances ([Fe/H], [O/Fe], and [\alpha/Fe]) from high resolution
spectroscopy for a sample of about thirty subdwarfs. Systematic effects due to
star selection (Lutz-Kelker corrections to parallaxes) and to the possible
presence of undetected binaries in the sample of bona fide single stars are
examined, and appropriate corrections are estimated. They are found to be small
for our sample. The new data allowed us to reliably define the absolute
location of the main sequence (MS) as a function of metallicity. These results
are then used to derive distances and ages for a carefully selected sample of
nine globular clusters having metallicities determined from high dispersion
spectra of individual giants according to a procedure totally consistent with
that used for the field subdwarfs. Very precise and homogeneous reddening
values have also been independently determined for these clusters. We find that
HIPPARCOS parallaxes are smaller than the corresponding ground-based
measurements leading, in turn, to longer distance moduli ($\sim 0.2$ mag) and
younger ages ($\sim 2.8$ Gyr). The relation between the zero age HB (ZAHB)
absolute magnitude and metallicity for the nine programme clusters turns out to
be: $M_V(ZAHB) = (0.22\pm 0.09)([Fe/H]+1.5) + (0.49\pm 0.04)$. The
corresponding LMC distance modulus is $(m-M)_0=18.60\pm 0.07$. The age of the
bona fide old globular clusters (Oosterhoff II and BHB) based on the absolute
magnitude of the turn-off, a theoretically robust indicator, is: Age =
{11.8^{+2.1}_{-2.5}} Gyr.
