  Understanding the co-evolution of super-massive black holes (SMBHs) and their
host galaxies remains a key challenge of extragalactic astrophysics,
particularly the earliest stages at high-redshift. However, studying SMBHs at
high-redshift with cosmological simulations, is challenging due to the large
volumes and high-resolution required. Through its innovative simulation
strategy, the First Light And Reionisation Epoch Simulations (FLARES) suite of
cosmological hydrodynamical zoom simulations allows us to simulate a much wider
range of environments which contain SMBHs with masses extending to
$M_{\bullet}>10^{9}\ M_{\odot}$ at $z=5$. In this paper, we use FLARES to study
the physical properties of SMBHs and their hosts in the early Universe ($5\le\,
z \le10$). FLARES predicts a sharply declining density with increasing
redshift, decreasing by a factor of 100 over the range $z=5\to 10$. Comparison
between our predicted bolometric luminosity function and pre-\emph{JWST}
observations yield a good match. However, recent \emph{JWST} observations
appear to suggest a larger contribution of SMBHs than previously observed, or
predicted by FLARES. Finally, by using a re-simulation with AGN feedback
disabled, we explore the impact of AGN feedback on their host galaxies. This
reveals that AGN feedback results in a reduction of star formation activity,
even at $z>5$, but only in the most massive galaxies. A deeper analysis reveals
that AGN are also the cause of suppressed star formation in passive galaxies
but that the presence of an AGN doesn't necessarily result in the suppression
of star formation.
