As Secretary of State for Scotland, he attended a reception for overseas heads of state and guests at Buckingham Palace and was also at Monday’s historic state funeral at Westminster Abbey.
However, one of the most solemn and memorable events for him was standing guard last Thursday beside The Queen’s coffin during her four-day lying-in state in Westminster Hall.
He officiated, largely head bowed, with Defence Secretary Ben Wallace, the defence secretary, in their voluntary role as members of the Royal Company of Archers.
Mr Jack, a bodyguard for 14 years, said: “It was a very moving experience and a privilege to be able to pay tribute to The Queen in this way. Her contribution to our country and other parts of the world has been widely acknowledged.
“Many of my constituents have spoken warmly of Her Majesty in recent days and her visits to Dumfries and Galloway. During more than 70 years as Queen she clearly created many happy memories amongst people locally. She is especially fondly remembered for her compassion, humour and warmth.”
As we reported last week, Mr Jack also had key roles in both Edinburgh and London in the days following the late monarch’s death and the accession of the new king, to whom he has pledged his support.