  We have examined the star formation history (SFH) of Andromeda VII (And VII),
the brightest and most massive dwarf spheroidal (dSph) satellite of the
Andromeda galaxy (M 31). Although M 31 is surrounded by several dSph companions
with old stellar populations and low metallicity, it has a metal-rich stellar
halo with an age of 6$-$8 Gyr. This indicates that any evolutionary association
between the stellar halo of M 31 and its dSph system is frail. Therefore, the
question is whether And VII (a high-metallicity dSph located $\sim$220 kpc from
M 31), can be associated with M 31's young, metal-rich halo. Here, we perform
the first reconstruction of the SFH of And VII employing long-period variable
(LPV) stars. As the most-evolved asymptotic giant branch (AGB) and red
supergiant (RSG) stars, the birth mass of LPVs can be determined by connecting
their near-infrared photometry to theoretical evolutionary tracks. We found 55
LPV candidates within two half-light radii, using multi-epoch imaging with the
Isaac Newton Telescope in the $i$ and $V$ bands. Based on their birth mass
function, the star-formation rate (SFR) of And VII was obtained as a function
of cosmic time. The main epoch of star formation occurred $\simeq 6.2$ Gyr ago
with a SFR of $0.006\pm0.002$ M$_\odot$ yr$^{-1}$. Over the past 6 Gyr, we find
slow star formation, which continued until 500 Myr ago with a SFR
$\sim0.0005\pm0.0002$ M$_\odot$ yr$^{-1}$. We determined And VII's stellar mass
$M=(13.3\pm5.3)\times10^6$ M$_\odot$ within a half-light radius
$r_{\frac{1}{2}}=3.8\pm0.3$ arcmin and metallicity $Z=0.0007$, and also derived
its distance modulus of $\mu=24.38$ mag.
