  The classification of homogeneous quaternionic manifolds has been done by
Alekseevskii, Wolf et al using transitive solvable group of isometries. These
manifolds are not generically symmetric, but there is a subset of quaternionic
manifolds that are symmetric and Einstein. A further subset of these manifolds
are the magic square manifolds. We show that all the symmetric quaternionic
manifolds including the magic square can be succinctly classified by
constrained instantons. These instantons are mostly semilocal, and their
constructions for the magic square can be done from the corresponding
Seiberg-Witten curves for certain N = 2 gauge theories that are in general not
asymptotically free. Using these, we give possible constructions, such as the
classical moduli space metrics, of constrained instantons with exceptional
global symmetries. We also discuss the possibility of realising the Kahler
manifolds in the magic square using other solitonic configurations in the
theory, and point out an interesting new sequence of these manifolds in the
magic square.
