Tianzi

Son of Heaven, Emperor.

Wang

King, the highest title conferred by the Emperor. Usually only reserved for the Royal Family. There are only a few exceptions that someone is conferred the title Wang. Such as a person obtaining the Emperor's life-saving grace may be conferred the title Wang by the Emperor himself, bestowing them with a rank that is equal to that of royalty. 

They may also be bestowed with a 'Kingdom' under the reign of the Empire or a Vassal State obtained by the Empire,  by the Emperor.

If someone who is not conferred the title Wang by the Emperor refers to themselves as such, it will be seen that they are raising a rebellion.

Gong

Duke, the second-highest title conferred by the Emperor. Usually given to those who contributed to the Empire. Mostly given to the Generals or High ranking officials. The family of the duke will also be given a region within the Empire for them to manage.

Hou

Marquise, a title under Gong. They are usually a title given to those who obtain the favor of the Emperor. They are also given land for them to manage but if problem arises, they will first report it to the Gong who governs the region where their land is located. Only if the Gong is incapable of solving the problem do they forward it to the Emperor.

Bo

Count. 

Zi

Viscount. Also used to refer as the 'Son of (title). For example, Gongzi is the son of a Duke, Nanzi is the son of a Baron. 

Nan

Baron

Jun

Lord.