The Objective of Sayyidna Yusuf (علیہ السلام) was to Establish the Din of Allah.

Said in verse 55 was:

وَكَذَٰلِكَ مَكَّنَّا لِيُوسُفَ فِي الْأَرْ‌ضِ يَتَبَوَّأُ مِنْهَا حَيْثُ يَشَاءُ ۚ نُصِيبُ بِرَ‌حْمَتِنَا مَن نَّشَاءُ ۖ وَلَا نُضِيعُ أَجْرَ‌ الْمُحْسِنِينَ

And thus We gave Yusuf (علیہ السلام) power in the land. He could settle there wherever he wished. We extend Our mercy to whomsoever We will, and We do not waste the reward of those who are good in deeds.

For details, it can be said that, after an experimental period of one year, the king of Egypt arranged a special celebration in his court to which he invited all officials and dignitaries of the state. Sayyidna Yusuf (علیہ السلام) was brought into the gathering with a crown on his head. Sayyidna Yusuf (علیہ السلام) was given, not simply the charge of the state treasury, but the charge of virtually the whole state. Having done this, the king him-self retired from active involvement with the affairs of the state. (Qurtubi, Mazhari and others)

Sayyidna Yusuf علیہ السلام managed the affairs of the state with such ability that no one had any reason to complain. The whole country loved him. Peace and prosperity prevailed all over. Even Sayyidna Yusuf (علیہ السلام) himself faced no problems or pains in executing the many responsibilities of the government.

Tafsir authority, Mujahid, has said: Since Sayyidna Yusuf (علیہ السلام) under the surface grandeur of his rule over the country, aimed at nothing but that the command of Allah Ta ala be carried out there and that the faith given by Him becomes firmly established. Therefore, he never lost sight of his basic objective, that is, inviting the king of Egypt to faith and Islam. As time passed, his efforts bore fruits by the grace of Allah and the king of Egypt too became a believing Muslim.