According to one legendary narrative, when Alexander the Great invaded India in 326 BC, he was confronted, for the first time, by the heroism of the brave king, Porus (the Indian ruler of the north western region).
Roxana (or Roshanak, Alexander’s wife) sent a Rakhi (sacred thread) for Porus to wear on his wrist, requesting him not to harm her husband in battle.
In accordance with tradition, Porus, a Katoch king, gave full respect to the Rakhi sent by Roxana.
On the battlefield, when Porus was about to deliver a final blow to Alexander, he saw the Rakhi on his own wrist and restrained himself from attacking Alexander.
He in return promised Alexander that he will cooperate with him in his Indian venture.