After Theseus got the golden sword , King Aegeus wanted to meet this great hero, he realized this hero was his son. He told Theseus about a monster(the Minotaur) and how people were sacrificed to fight it. Theseus volunteers to fight it.
Theseus and everyone else got captured by King Minos, but then Ariadne, daughter of King Minos, found them and helped Theseus escape with a ball of string.
Theseus angrily stomped through the corridors of the labyrinth following the ball of string leading to to the Minotaur.
Take Me Lord!
He found the evil Minotaur and defeated him. No one else had to be sacrificed ever again.
After Theseus defeated the Minotaur, he got on the ship on his way to Athens.
On his way to Athens, Theseus forgot to change his sail from black to white, and King Aegus jumped off the boat thinking his son was dead and Theseus became the new king.