We report on the evolution of lateral ordering of SiGe nanoscale islands on Si(001), which have been grown by means of liquid phase epitaxy in the Stranski-Krastanow mode. Applying post-growth atomic force microscopy on different sample areas covered by different island densities, we could trace ex-situ the development of extended island chains along the <100>-directions. The linear alignment happens by further nucleation of islands at the end of an already existing formation. Those direct observations will be discussed in terms of finite element strain energy calculations around various island configurations.