  The Gaia-ESO Survey is obtaining high-quality spectroscopic data for about
10^5 stars using FLAMES at the VLT. UVES high-resolution spectra are being
collected for about 5000 FGK-type stars. These UVES spectra are analyzed in
parallel by several state-of-the-art methodologies. Our aim is to present how
these analyses were implemented, to discuss their results, and to describe how
a final recommended parameter scale is defined. We also discuss the precision
(method-to-method dispersion) and accuracy (biases with respect to the
reference values) of the final parameters. These results are part of the
Gaia-ESO 2nd internal release and will be part of its 1st public release of
advanced data products. The final parameter scale is tied to the one defined by
the Gaia benchmark stars, a set of stars with fundamental atmospheric
parameters. A set of open and globular clusters is used to evaluate the
physical soundness of the results. Each methodology is judged against the
benchmark stars to define weights in three different regions of the parameter
space. The final recommended results are the weighted-medians of those from the
individual methods. The recommended results successfully reproduce the
benchmark stars atmospheric parameters and the expected Teff-log g relation of
the calibrating clusters. Atmospheric parameters and abundances have been
determined for 1301 FGK-type stars observed with UVES. The median of the
method-to-method dispersion of the atmospheric parameters is 55 K for Teff,
0.13 dex for log g, and 0.07 dex for [Fe/H]. Systematic biases are estimated to
be between 50-100 K for Teff, 0.10-0.25 dex for log g, and 0.05-0.10 dex for
[Fe/H]. Abundances for 24 elements were derived: C, N, O, Na, Mg, Al, Si, Ca,
Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, Nd, and Eu. The typical
method-to-method dispersion of the abundances varies between 0.10 and 0.20 dex.
