Because he was gifted by God to interpret dreams and he was able to interpret Potiphar's dream. He was also to resolve the famine issues that plagued Egypt and devised a solution to ration Egypt's resources in such a way that they were able to survive the famine. This led to Pharoah making him 2nd in command of all of Egypt's affairs.
Potiphar, one of Pharaoh's ministers.
He worked for Potiphar
Potiphar was the Sar Hatabachim of Pharaoh (Genesis ch.39). Some translate this as Pharaoh's chief executioner (Targum), while others translate it as the chief butcher (Rashi commentary). Joseph was purchased as a slave by Potiphar, and served in his house (Genesis 39).
Joseph was, for a time, head of Potiphar's household. This gave him leadership experience.
Potiphon does not exist. You prabably mean Potiphar, who was Pharoah's butcher in the story of Joseph. When Joseph arrived in Egypt as a slave he was sold to Potiphar. Potiphar liked Joseph and made him head slave, but Potiphar's wife was jealous, and tricked Potiphar into throwing Joseph in jail.
Genesis 37:36 And the Midianites sold him into Egypt unto Potiphar, an officer of Pharaoh's, and captain of the guard.
They sold him to Potiphar, the chief of Pharaoh's bodyguard in Egypt.(Genesis 37:21-28, 36; 39:1)
According to the bible Joseph was sold by his brothers to some traders going to Egypt. Joseph was later sold to Potiphar the captain of the palace guard. Joseph find favour with Pharaoh when he interprets a dream of pharaoh's. Pharaoh is pleased with Joseph and makes him governor of all Egypt. You can read the story in Genesis chapt 37 - 40
Potiphar promoted Joseph a couple of times, as alluded to in the wording of Genesis 39. At first, Joseph was put among the field-workers. Later, he was promoted to be one of the household staff. Still later, he was made one of Potiphar's personal manservants; and finally, Joseph was made the one who ran the entire house. See also:More about Joseph
Joseph was sold into slavery in Egypt. Potiphar bought Joseph and eventually Joseph found favor with his master and was put in charge of his household. But Potiphar's wife had eyes for the young strong man trying to entice him to go to bed with her. Finally one day Potiphar's wife grabbed Joseph but he pulled away from her and she accused him of rape. And so Potiphar had him placed in prison. Joseph knew that it would have been a sin to go to bed with another man's wife so He refused even though it cost him prison time.
He tells her that he is the head of Potiphar's posessions, but he has no right to Potiphar's wife. He also says that he would not be honoring God if he did what Potiphar's wife wanted.
She tried to make Joseph come to bed with her. Joseph ran away, because he wouldn't be honoring God or his master by doing something as sinful as what Potiphar's wife wanted.