Prince William, 38, was given the role in 2020 but the General Assembly was cancelled last May due to the pandemic.
According to the royal family's website, the Lord High Commissioner's role is to maintain the relationship between the State and the Church, and a long-standing tradition of appointing a Lord High Commissioner originated in the latter part of the 16th Century.
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It adds: "The Lord High Commissioner makes opening and closing addresses to the General Assembly and reports to Her Majesty on its proceedings.
"For the duration of the General Assembly, the Sovereign grants the Lord High Commissioner permission to reside at the Palace of Holyroodhouse and, during this time, His or Her Grace receives a Guard of Honour, a 21-Gun Salute and the keys to the City of Edinburgh.
"It is also customary for the Lord High Commissioner to invite distinguished guests to stay at the Palace, and to offer hospitality to Commissioners to the Assembly and those who have contributed to public life in Scotland."
William and Kate in Dundee in 2019
William and wife Kate are known as the Earl and Countess of Strathearn in Scotland.
The Church of Scotland is a Presbyterian church and recognises only Jesus Christ as 'King and Head of the Church'. The Queen therefore does not hold the title 'Supreme Governor' of the Church of Scotland; when attending church services in Scotland Her Majesty does so as an ordinary member.
Other members of the royal family have been appointed to the role in the past, including Princess Anne twice, Prince Charles (who is known as the Duke of Rothesay in Scotland), Prince Andrew and Prince Edward.
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