Khan was unsatisfied with King Zahir Shah's constitutional parliamentary system and lack of progress. He planned rebellion for more than a year before he, on 17 July 1973, seized power from the King in a bloodless coup, backed by a large number of army officers who were loyal to him, facing no resistance. Departing from tradition, and for the first time in Afghan history, he did not proclaim himself "Shah", establishing instead a republic with himself as President. The role of pro-communist Parchamite officers in the coup led to him receiving the nickname "Red Prince" by some.