The representation of an explicit solution to the Prabhakar fractional
differential delayed system is studied employing the far-famed Laplace
transform technique. Second, the existence uniqueness of the solution is
debated together with the Ulam-Hyers stability of a semilinear Prabhakar
fractional differential delayed system. Thirdly, the necessary and
sufficient circumstances for the controllability of linear Prabhakar
fractional differential delayed system are determined by describing the
Gramian matrix. A sufficient circumstance for the relative
controllability of a semilinear Prabhakar fractional differential
delayed system is studied via the Krasnoselskii's fixed point theorem.
Numerical examples are offered to verify the theoretical findings.