Tens of thousands of Orange Order members and supporters are taking part in Twelfth of July parades at 18 locations across Northern Ireland on the biggest day in the calmest marching season for decades.
Northern Ireland marked one of its most relaxed July 12th in more than 30 years.
By early evening, there had been no trouble during any of the parades marking the Battle of the Boyne in 1690. Organisers were hoping there would be no violence later tonight when many loyalists return home.
Processions through flashpoint areas of earlier years in west and north Belfast passed off peacefully today and the security presence was low-key.
Some estimates put the number attending today's key events at 400,000.
A sea of orange-clad demonstrators travelled down main streets alongside scores of bands and supporters waving Union flags.
Police chiefs appealed for calm ahead of today's events and said they were confident violent outbreaks of previous years would not be repeated. "Last year was one of the most peaceful parading seasons for many years. We hope and expect a similar situation this year," a police statement said.
A key "feeder" parade passed peacefully through republican Ardoyne in north Belfast this morning on its way to the main demonstration.
Republican residents held a small demonstration as they passed. Serious violence erupted at Ardoyne in 2005 as the parade returned through the area on its way back from the main event. A repeat was avoided last year following intensive local efforts to avoid trouble.
Key speakers at fields across the North will include former Orange Grand Master Martin Smyth in Ballymena, Co Antrim; Orange historian David Hume in Belfast; and MPs Willie McCrea in Limavady, Co Derry and Jeffrey Donaldson in Maghaberry, Co Antrim.
Democratic Unionist leader the Rev Ian Paisley addressed crowds at Ballymoney as head of the Independent Orange Order.
The marching season so far this year has been the most peaceful in decades. Key Orange parades in north and west Belfast and at Drumcree, Co Armagh, have all passed off without major incident. In Belfast, the so-called Tour of the North march and the Whiterock parade ended peacefully.
Most businesses in Northern Ireland are closed for the annual holiday.
Hundreds of bonfires were lit in loyalist areas across Northern Ireland last night as a traditional prelude to today's parades.
Firefighters came under attack while attending emergency calls at a number of bonfires. Fire engines were damaged in west Belfast and stones were hurled at bonfire sites in Portadown, Co Armagh, and Banbridge, Co Down.
The Fire Service said the number of calls received last night was 40 per cent down on last year, however. There were almost 200 bonfire-related calls in total. "The majority of calls were dealt with without incident," a spokesman said.
Today's events commemorate the 1690 victory of Protestant King William over Catholic King James in the Battle of the Boyne.