Yesterday was Raksha Bandhan, the Hindu festival celebrating love between brothers and sisters. On Raksha Bandhan (which literally translates to binding protection), sisters tie decorated sacred threads, called Rakhis, around their brothers wrists.

With this act, sisters pray for their brothers to be protected from all evil, and in return brothers promise to protect their sisters from all harm and troubles. He also gives her a return gift which is a physical acceptance of her love, a reminder of their togetherness and a symbol of his pledge. A tenner normally does the trick.

It's not just between siblings however, I recieve Rakhis from my cousins also, and even good friends tie them to each other.

Like all Hindu festivals, Raksha Bandhan follows the moon calendar, and falls on the full moon of the month of Shravaan - the holiest month in the Hindu calendar.

There are many legends surrounding Raksha Bandhan and events in history in which the festival features:

The oldest reference to the festival of rakhi goes back to 300 B.C. at the time when Alexander invaded India.
It is said that the great conqueror, King Alexander of Macedonia was shaken by the fury of the Indian king Puru in his first attempt.
Upset by this, Alexander's wife, who had heard of the Rakhi festival, approached King Puru. King Puru accepted her as his sister and when the opportunity came during the war, he refrained from Alexander.

My favourite however, is the story of Krishna and Draupadi (the wife of the Pandavs) in the Mahabharat.

When Krishna injured his wrist whilst fighting in the war, Draupadi tore a strip of silk off her sari and tied it to stop the blood flow.
Krishna was so touched by her action that he found himself bound to her by love.

Later, Draupadi was kidnapped by the evil Duryodhan and was forced to be made a slave in his court. He commanded Dushashan to remove clothes of Pandavas and Draupadi as they were now his servants.
The Pandavas surrendered without any resistance. Now Dushashan turned to Draupadi. It was a moment of shame for mighty Pandavas yet they were helpless and remained silent spectators.
Draupadi was in a state of complete helplessness. Her five husbands were unable to save her. Elders in the assembly turned deaf ears to her intense call for help. Dushashan began pulling her sari off infront of the whole court so she prayed with all her faith to Lord Krishna.

Krishna heard Draupadi's prayers and remembering how she had tied Rakhi on him, came to her rescue. With his extraordinary powers, Krishna gave Draupadi one sari for every thread of silk in the Rakhi she had given him, and as one was pulled off, another would magically appear.
In the end, Dushashan fell to the ground exhausted and Draupadi was saved.