Perhaps most important consideration... in determining Nerva's selection was the age of the new emperor. At least in his mid 60's Nerva was reportedly in poor health and as suggested by Suetonius, only the astrology that predicted Nerva's imminent natural death prevented Domitian from having him executed anyway. This vulnerable status and the fact that Nerva had no direct male heirs with whom to continue another family dynasty, allowed the Senate to use him as an interim emperor, until another suitable candidate could be found. Nerva's complete lack of military experience also prevented a potential for a legionary revolt based on loyalties to slightest generals. Military candidates to the imperial throne such as Trajan understood that Nerva's appointment was a stopgap measure and that the real game was not played by succeeding Domitian but would be won as Nerva's heir.