…Constantine himself suffers a humiliating defeat at the hands of Kardam of Bulgaria in the 792 Battle of Marcellae.

The Bulgarians had built ramparts blocking the roads to the Rish Pass and the capital Pliska.

The emperor did not dare to attack for several days but by the end of July he was persuaded by "false astrologists" (according to the Byzantine chronicler Theophanes the Confessor) that the stars boded victory and attacked.

Before the beginning of the battle, while awaiting the imperial assault, the Bulgarian ruler secretly placed part of his cavalry behind the hills surrounding the battlefield.

Due to the rugged terrain the advancing imperial army breaks its order.

Taking advantage of this mistake, Kardam orders a counterattack that brings the Bulgarians a great success.

The Bulgarian cavalry goes around the imperial army and cuts their way back to their fortified camp and the fortress of Marcellae.

The Bulgarians take the supplies, the treasury and the tent of the emperor.

They chase Constantine VI to Constantinople, killing a great number of soldiers.

Many imperial commanders and officers perish in the battle.

A weapon called arkani is used by the Bulgarians in this battle: the arkani consists of a long pole with an attachment similar to a lasso at one end.

It is an excellent weapon against cavalry as the rider can easily be pulled out of the saddle by a skilled warrior armed with the arkani.

After the defeat, Constantine VI has to conclude peace with Kardam and has to pay tribute.