Severus Snape put it there at the request of Dumbledore.
Severus Snape but it was a pond not a river.
Godric Gryffindor.
The sword of gryffindor is used by the queen to knight people. It was created in 1604 on the 20th of June
No, though there is a scene where Harry strips down to his underwear before diving into the pond to retrieve Gryffindor's sword.
With the Gryffindor Sword.
The sword was Godric Gryffindor's sword.
Each of the founders have an item that was important to them. For Godric Gryffindor, this was his sword. He enchanted it so that if a true Gryffindor ever needed help it would come out of The Sorting Hat (which also belonged to him).
Harry used the sword of Godric Gryffindor.
A broken sword can be a symbol or defeat, or of peace.
Of course it is. And it's Gryffindor.
In a book, Hermione reads that the sword of Gryffindor only takes in that which makes it stronger. In Harry Potter and the Chamber of Secrets Harry uses the sword of Gryffindor to stab the basilisk in the basilisk's mouth; this means the sword contains basilisk venom which makes it stronger and it can kill horcruxes, just like the fang of the basilisk.
Severus Snape.