Do the colonists have justification to declare independence from great britain ?

Yes

The colonists in the Declaration of Independence clearly stated their grievances and made a case against England, declaring to the world the reasons that caused them to declare their independence and fight to become the United States of America. These include taxation without representation

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).

it provided for equal trade rights among nations in china.