  In this paper we collect results concerning the {operator-norm} convergent
{Trotter} product formula for two semigroups $\{\e^{- t A}\}_{t\geq 0}$,
$\{\e^{- t B}\}_{t\geq 0}$, with densely defined generators $A$ and $B$ in a
{Banach} space. Although the {strong} convergence in Banach space for
contraction semigroups is known since the seminal paper by Trotter (1959),
which after more than three decades was extended to convergence in the
{operator-norm} topology in {Hilbert} spaces by Rogava (1993), the
{operator-norm} convergence in a {Banach} space was established only in (2001).
