Bowline

The bowline ( /ˈboʊlɪn/ or /ˈboʊlaɪn/) is an ancient and simple knot used to form a fixed loop at the end of a rope. It has the virtues of being both easy to tie and untie. The bowline is sometimes referred as King of the knots because of its importance. It is one of the four basic maritime knots (the other three are figure-eight knot, reef knot and clove hitch).