It is known that Klaus has daggered Kol on numerous occasions over the centuries. However, despite this, Kol has forgiven Klaus for daggering him and his siblings and they now share a close relationship. Their current bond is unlike any close bond they ever or possibly might have shared throughout the centuries.

Who killed Kol Mikaelson?

When Kol tries to cut off Jeremy's hands, Elena intervenes and Jeremy kills Kol with the White Oak Stake. Klaus sees this, and threatens to burn the home to ground and that he is no longer worried about the cure or his hybrids. Meanwhile, Stefan tells Rebekah that Kol is dead and she is upset.

Who killed Kol the first time?

He antagonized the Mystic Falls Gang and at one point Elena Gilbert proposed a truce between them. However, the truce was really a setup to kill Kol and it ultimately led to his demise at the hands of Jeremy Gilbert in A View to a Kill.