By chance last week I met the descendant of Lord Harrowby who was the Lord President of the Council at the time of Waterloo and was entertaining the cabinet on the night the news in the hands of Major Henry Percy arrived.
Lord Harrowby’s residence was in Grosvenor Square, now No 44 the site of the Millennium Hotel, which is currently being renovated. Amongst the diners was Lord Bathurst who would be the recipient of the despatch. There was an air of anticipation as they knew news was imminent and they were about to break up and depart their separate ways when the carriage with the eagles sticking out arrived.
The subject of my conversation with the current Lord Harrowby centred round the 14-year -old daughter of Lord Harrowby who witnessed the incident. She watched from the top of the staircase through the bannisters. But no one knows the source of this account. Nevertheless this wonderful story is well told in a book published in 2015 called “The News From Waterloo” by Brian Cathcart. see https://www.amazon.co.uk/News-Waterloo-Britain-Wellingtons-Victory/dp/0571315259