Explain the procedure of nomination of candidates?

In the context of elections for public office, a candidate who has been selected to represent or is endorsed by a political party is said to be the party's nominee. ... Candidates who are endorsed by a political party may be required to submit a nominating petition in order to gain ballot access.

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).