In this paper, we have created highly uniform one-dimensional single (In,Ga)As QD arrays on planar GaAs (100) substrates by self-organized anisotropic strain engineering of an (In,Ga)As/GaAs quantum wire (QWR) superlattice (SL) template. During molecular beam epitaxy (MBE) of a strained (In,Ga)As/GaAs SL, elongated (In,Ga)As QDs develop into uniform QWR arrays with well-defined lateral periodicity. QWR formation relies on the anisotropic adatom surface migration and in desorption during annealing of the layers of elongated QDs after capping with a thin GaAs layer. The formation of highly uniform (In,Ga)As QD arrays with excellent PL properties is attributed to the smoothness of the strain field modulation on the dot-diameter and dot-to-dot ...