It was said to be impossible to be untied -and so it was cut asunder by sword, using 'the Alexandrian solution' -a bold stroke!
It was cut loose by Alexander (the Great) with a bold stroke of his sword, hence the term: the Alexandrian solution.
There are no evidence of that.
A man named Gordius secured his donkey with it.
because they both had a tied knot and had a huge reward for untieing it