The descendents of sailors who fought in the biggest naval battle of the First World War are gathering in Orkney to mark the 100th anniversary of the conflict.

Around 8600 British and German sailors were killed in the 36-hour Battle of Jutland off the coast of Denmark in spring 1916.

A service is being held at the UK's most northerly cathedral in Kirkwall to honour the war dead, which Prime Minister David Cameron and German President Joachim Gauck are expected to attend.

The Princess Royal will represent the Royal family at the memorial at St Magnus Cathedral, where thousands of ceramic poppies have been installed in tribute.

A specially-commissioned piece of music by the late composer and Orkney resident Sir Peter Maxwell Davies will be performed.

The Duke of Edinburgh was due to attend but was forced to cancel following doctor's advice.

First Minister Nicola Sturgeon was joined by Princess Anne and vice-admiral Sir Tim Laurence at a memorial in Rosyth earlier this week.

Descendants of those who fought at Jutland have been invited to join the commemorations, which will continue with a service at Lyness Cemetery on the island of Hoy - the final resting place for more than 450 service personnel who died in the war, including sailors killed at Jutland.

The cemetery stands close to Scapa Flow, from where the British Grand Fleet set out for the Jutland Bank to repel German forces attempting to break a British blockade.

Nearly 250 ships took part in the battle and both nations claimed victory - Germany because of the 6094 British losses compared to the 2551 men it sacrificed - but Britain had seriously weakened the enemy's naval capability.

There will also be a remembrance service at sea where British and German naval representatives will scatter poppies and forget-me-nots - the German flower of remembrance - into the North Sea at Jutland Bank.

The Government said the commemorations will remember all those who lost their lives. while also paying tribute to the role of the Royal Navy and the Orkney Islands in First World War.

Orkney Islands Council vice-convener Jim Foubister said: "We are proud to be hosting the UK's national commemoration of the Battle of Jutland.

"It is fitting that the Jutland commemorations will draw to a close among the graves of some of those who made the ultimate sacrifice for their countries a century ago."

Commemorative events marking the Jutland centenary have previously been held at Rosyth and South Queensferry on the Firth of Forth, from where the Battlecruiser force set sail ahead of the battle on May 31, 1916.