Varahran, however, was all the while preparing to fall upon them unawares.

He had started for Azerbijan with a small body of picked warriors; he had drawn some further strength from Armenia; he proceeded along the mountain line through Taberistan, Hyrcania, and Nissa (Nishapur), marching only by night, and carefully masking his movements.

In this way he reached the neighborhood of Merv unobserved.

He then planned and executed a night attack on the invading army which was completely successful.

Attacking his adversaries suddenly and in the dark--alarming them, moreover, with strange noises, and at the same time assaulting them with the utmost vigor--he put to flight the entire Tatar army.