The Duke of Cambridge will meet Chancellor Angela Merkel for the first time at a gala in Germany tonight.
William, who is visiting Dusseldorf for a series of events honouring the role of British armed forces based in Germany, is set to attend a ceremony with the German stateswoman on Tuesday evening.
The gala will mark the 70th anniversary of the state of North Rhine-Westphalia - which was created by the British military government in 1946 after the Second World War.
"Operation Marriage" merged the regions of North Rhine, part of the largely Catholic Rhineland, and the predominantly Protestant Westphalia. A close link between Britain and the North Rhine-Westphalia state has endured since, partially thanks to the continued military presence.
William is expected to deliver a speech during a ceremony in the city's Tonhalle where the history of the North Rhine-Westphalia state will be celebrated with musical performances and short films.
Mrs Merkel, who will have just returned from a post-Brexit meeting to relaunch the EU project with Italian premier Matteo Renzi and French president Francois Hollande, will also speak at the gala.
Prior to the gala, the Duke will watch a British Forces Germany (BFG) military parade with the region's minister, President Hannelore Kraft, and meet BFG personnel at a reception.
He will see the 20th Armoured Brigade receive the Fahnenband - the federal state's highest military honour - in recognition of their service to the defence of Germany.
William, who is carrying out the official visit at the request of the Government, will then meet servicemen and women and their families at Dusseldorf's NRW Forum.
Britain has had a large military presence in the region for 70 years. Around 27,000 British citizens live in the state and 1,400 British firms are based there.
However, British troops based in the region are being withdrawn under the Army Basing programme which began six years ago. It seeks to bring all UK military units back from Germany by 2020. By the end of this year, just 3,600 personnel will be left in Germany.