More than 600 police officers are being drafted in from Britain to help police the 12th of July parades in the North.
550 parades are taking place today and thousands of Orangemen will take part.
Marchers in Belfast will not be allowed walk back through the Ardoyne on the return leg – after a decision by the Parades Commission earlier this week.
In recent years there has been serious rioting in the nationalist Ardoyne area after the parade.