  We have implemented a simple model to identify the likely sites of the first
stars and galaxies in the high-resolution simulations of the formation of
galactic dark matter halos of the Aquarius Project. The first star in a galaxy
like the Milky Way formed around redshift z=35; by z=10, the young galaxy
contained up to 30000 dark matter haloes capable of forming stars by molecular
hydrogen cooling. These minihaloes were strongly clustered and feedback may
have severely limited the actual number of Population III stars that formed. By
the present day, the remnants of the first stars would be strongly concentrated
to the centre of the main halo. If a second generation of long-lived stars
formed near the first (the first star relics), we would expect to find half of
them within 30kpc/h of the galactic centre and a significant fraction in
satellites where they may be singled out by their anomalous metallicity
patterns. The first halo in which gas could cool by atomic hydrogen line
radiation formed at z=25; by z=10, the number of such first galaxies had
increased to ~300. Feedback might have decreased the number of first galaxies
at the time they undergo significant star formation, but not the number that
survive to the present because near neighbours merge. Half of all the "first
galaxies" that form before z=10 merge with the main halo before z~3 and most
lose a significant fraction of their mass. However, today there should still be
more than 20 remnants orbiting within the central ~30kpc/h of the Milky Way.
These satellites have circular velocities of a few kilometers per second or
more, comparable to those of known Milky Way dwarfs. They are a promising
hunting ground for the remnants of the earliest epoch of star formation.
