11.   Robes remained the vogue, but there was no traditional street march.

12.   Sectarian violence broke out in parts of Northern Ireland last summer when Catholics attempted to stop pro-British Unionists holding traditional marches through towns in the province.

13.   The catalyst was a traditional Protestant march that police for four days blocked from passing through the main Catholic part of a town called Portadown.

14.   The issue of traditional Protestant marches inflames sectarian passions in Northern Ireland.

15.   The issue of traditional Orange marches, and Catholic opposition to them, sparked riots throughout Northern Ireland in July.

16.   The protesters say they are retaliating because Catholics this summer tried to reroute traditional pro-British Protestant marches away from Catholic areas.

17.   The protests followed a summer when Catholic militants blocked traditional Protestant marches, sparking riots in both communities.

18.   The traditional Orange marches each summer spark sectarian tempers, underscoring for many Catholics a sense of second-class citizenship in this Protestant-majority province.

19.   Then Prince Philip joined ranks of veterans in a traditional march past the monarch.

20.   This tension is expected to increase once traditional Protestant marches start in July.