Thousands of Orange Order members will take part in parades across Northern Ireland today as part of the 'Twelfth of July' celebrations.
The events mark King William of Orange's victory over James II at the Battle of Boyne in Ireland in 1690.
Overnight, huge 'Eleventh night' bonfires ushered in the main date in the Protestant loyal order calender.
Firefighters in the region dealt with 40 bonfire related incidents - up 21% on last year - on a night when they received 213 emergency calls in total and mobilised to 133 incidents overall - a 49% hike on 2016.
The Northern Ireland Fire and Rescue Service (NIFRS) described the night as "exceptionally busy", with crews dealing with 95 operational incidents between 10pm and 1am. During the most intense period, the NIFRS's regional control centre handled an emergency 999 call every minute.
Homes were boarded up at a number of bonfire sites amid concerns around safety and risk to property.
Firefighters doused at-risk buildings with water in an effort to keep them cool as the fires raged nearby.
The NIFRS said its two most significant bonfire incidents were in the greater Belfast area. The service also reported one attack on a fire appliance during the night - though no one was injured.
The towering bonfires, most built with stacks of wooden pallets, drew thousands of onlookers into the early hours of Wednesday.
The bonfires often prove contentious and this year was no different.
Sinn Fein reacted angrily to a coffin bearing an image of the late Martin McGuinness being attached to one in east Belfast, while Irish flags and posters of Sinn Fein and other non-unionist politicians were a common sight on many fires.
As the embers from the Eleventh night fires smoulder, loyalists are looking ahead to Wednesday's Twelfth festivities.
While the vast majority of the almost 600 Protestant loyal order parades on the day are free of trouble, the threat of disorder at a small number of flashpoints always has the potential to mar proceedings.
There is cautious optimism this year's Twelfth will pass off without major incident.
Orangemen and nationalist residents at the most contentious parade - at Woodvale/Ardoyne in north Belfast - have struck a deal that aims to reduce tensions in the area. That community interface has been the scene of violence in recent years.
A total of 18 venues will be hosting parades across the region.
The Co Armagh village of Richhill will host the largest Twelfth parade. Eleven district lodges with 154 private lodges and 70 bands from the historic county, where the Orange Order was formed in 1795, will provide a highly colourful spectacle for the expected influx of 25,000 people.
A large Scottish contingent is expected in Belfast, as the city holds the longest Twelfth parade on the day, with participants walking over six miles to the field.
Alongside Ballymena, the capital stages a Twelfth demonstration every year.
Other demonstrations will be held in Lisbellaw, Cookstown, Beragh, Clogher, Coleraine, Kilrea, Banbridge, Bangor, Ballynahinch, Annalong, Hillsborough, Cloughfern, Broughshane, Ballymena, Cloughmills and Cullybackey.