The black Knight had confrontation with Sir Lancelot since they were teenagers. This consisted of hand to hand fighting.
The Black Night Wonders Off
The fighting didn't seem to stop for decades, and eventually Sir Gawain intervened and told them to stop fighting.
The two finally end their feud, but they did not end up conquering one another
The Black Night Meets His Father
You're my WHAT?!
The black night ended up riding into the forest with his trusty horse
Finally the black night arrived at King Arthur's castle where he battled with him.
In the end whilst the black night is still in King Arthur's castle, he meets a servant there who turns out to be his real father. The black night then went back to his castle and not much was heard from him or his father ever again.
I have some very shocking news. I am your real father...