Stabbed with his own dagger

"AAAHHHH!!!" After another day passed, a loud shriek erupted from atop the capital's main gate, the Duke finally understood what was going on around him.

The Burton family's army had allowed its spies and scouting squads to keep tabs on their slow march from day one, until they came within a day's distance from the capital, then they began hunting down and killing the spies and scouting squads.

After they made sure no one is watching anymore, they divided themselves into 6 equal armies and encircled the capital, attacking all the towns and villages around it, 

taking advantage of the situation as these cities and villages had become defenseless.

The operation was carried out with incredible speed and accuracy, in just 48 hours every inch of the Duchy of Harris, except for the capital, became under the Burtons rule!!