By Mark Simpson BBC Ireland correspondent in Belfast

For the first time in recent memory, the summer marching season in Northern Ireland has passed off without major violence. BBC Ireland Correspondent Mark Simpson examines the reasons behind this rare period of calm.

The words "quiet", "summer" and "Northern Ireland" are seldom found in the same sentence.

Normally, when someone is about to put pen to paper about a period of peace, a huge riot erupts somewhere in Belfast.

This year was different. For once, when people said it was a long, hot summer in Northern Ireland, it was a comment on the weather rather than the security situation.

The annual service at Drumcree Church passed without incident

Even Drumcree was peaceful. The last time that happened, the Tories were still in power and Sir Patrick Mayhew was Secretary of State.

So can the current Secretary of State, Paul Murphy, take the credit for this year's summer of calm?

Were the Orange Order more accommodating than usual?

Did Catholic resident groups deliberately tone down their protests?

Did the IRA make a strategic decision to calm things down, rather than stir things up?

Or did the police simply control the situation better than they had done previously?

The answer is that no one person - or organisation - can take the plaudits for the relative peace.

It was the first summer in charge for Northern Ireland's new Chief Constable Hugh Orde, but he doesn't believe he himself made a difference.

"I claim no credit for it but I think the police service can claim credit for it," says Mr Orde.

Hugh Orde praised the PSNI's role in maintaining calm on the streets

"Officers at every level have worked with opinion-formers from all sorts of communities and organisations. It did not happen by accident."

In July last year, the overtime bill for the police service was �3m above budget. This year, it was �1.5m UNDER bugdet.

What helped the police do their job was that a number of known trouble-makers within loyalism were off the streets. The feud within the UDA earlier in the year led to some leaving the country while others were jailed.

The UDA ceasefire - in spite of its flaws - was another important factor. For political reasons, it seems loyalists wanted a quiet summer.

A period of calm also fitted in with the agenda of the republican movement. Sinn Fein spent the spring trying to convince unionists that the IRA was now dormant. Gerry Adams will now be telling unionists that during the summer, actions spoke louder than words.

Republicans have been critical of the Orange Order and other Protestant marching groups for refusing to talk to Catholic residents in the areas where parades take place.

But there are signs of that policy being diluted, for example in Londonderry where the Apprentice Boys spoke to the local resident group.

The summer has not been as volatile as previous years where rioting was common

The vice-chairman of the Policing Board, Denis Bradley, is relieved that July and August passed off without major incident.

He says: "I think that the political parties, and some of the paramilitary groupings decided 'we're not going to get into turmoil here because there's nothing in it for us - it's better to have a reasonably quiet summer'.

"But I also think this is a dangerous moment for Northern Ireland.

"I think that within British politics, there is a kind of complacency."

Mr Bradley fears the government will look at the events of recent months and think that there is no urgent need to resolve Northern Ireland's ongoing political problems.