sia
Minor, who had long been Persian subjects. It was they who had bridged
the Danube, and who were left to guard the bridge. After Darius had
crossed the bridge, on his march north, he ordered the Ionians to break
it down and follow him into Scythia, leaving only the rowers and seamen
in the ships. But one of his Greek generals advised him to let the
bridge stand under guard of its builders, saying that evil fortune might
come to the king's army through the guile and shrewdness of the
Scythians.

Darius found this advice good, and promised to reward its giver after
his return. He then took a cord and tied sixty knots in it. This he left
with the Ionians. "Take this cord," he said. "Untie one of the knots in
it each day after my advance from the Danube into Scythia. Remain here
and guard the bridge until you shall have untied all the knots; but if
by that time I shall not have returned, then depart and sail home."

Such were the methods of counting which then prevailed. And the
knowledge of geography was not more advanced. Darius had it in view to
march round the Black Sea and return to Persia along its eastern
side,--with the wild idea that sixty days would suffice for this great
march.

Fortunately for him, as the story goes, the Ionians did not obey orders,
but remained on guard after the knots were all untied. Then, to their
surprise, Scythians instead of Persians appeared. These told the Ionians
that the Persian army was in the greatest distress, was retreating with
all speed, and that its escape from utter ruin depended on the safety of
the bridge. They urged the Greeks to break the bridge and retire. If
they should do so the Persians would all be destroyed, and Ionia would
regain its freedom.

This was wise advice. Had it been taken it might have saved Greece from
the danger of Persian invasion. The Ionians were at first in favor of
it, and Miltiades, one of their leaders, and afterwards one of the
heroes of Greek history, warmly advised that it should be done. But
Histiaeus, the despot of Miletus, advised the other Ionian princes that
they would lose their power if their countries became free, since the
Persians alone supported them, while the people everywhere were against
them. They determined, therefore, to maintain the bridge.

But, to rid themselves of the Scythians, they pretended to take their
advice, and destroyed the bridge for the length of a bow-shot from the
northern shore of the stream. The Sc