爱尔兰总统首次访英
The first official visit to the UK by an Irish head of state is due to get under way.
爱尔兰国家领导人对英国的首次正式访问即将启动。
The Queen shook hands with Martin McGuinness during a trip to Belfast two years ago
President Michael D Higgins will meet the Queen and address Parliament - another historic first.
Ahead of the trip he said Anglo-Irish relations were at a high but warned there was "significant work" to do secure peace in Northern Ireland.
Ireland won independence in 1921 following a civil war and guerrilla campaign against British forces.
However, six counties were kept under British control, creating Northern Ireland.
For centuries Ireland was under British or English rule and the more recent troubles can be traced back to the partition of the country.
President Higgins said there were "a lot of very difficult memories" and that it would be wrong to "wipe the slate clean".