Northern Ireland First Minister Mr David Trimble has called for a calm during the Portadown Orange Lodge march to Drumcree in County Armagh today.
He was speaking ahead of the controversial parade last night as a large-scale security operation involving more than 2,000 Police Service of Northen Ireland officers and four British army battalions.
Last Friday the Parades Commission upheld its decision to ban the Orange Order from walking on the Garvaghy Road in Portadown for the fifth successive year.
PSNI Assistant Chief Constable Stephen White said he thought this year's march would be "peaceful and dignified" and added there would still be a large police and British army presence in Portadown today.