London: Prince Harry, who went on a charity trip to the Arctic earlier this year, kept the visit secret from his grandmother Queen Elizabeth as he believed she would think he was "completely mad".
The 26-year-old Harry took part in the "Walking With The Wounded" trek in April in which he battled sub-zero temperatures, a newspaper reports.
He has said in a BBC documentary titled "Harry`s Arctic Heroes" that his father Prince Charles was nervous about the trip.
"My father obviously knew I was coming out here and so did my brother. But I kind of kept it quiet - I don`t know why it happened - so my grandparents and the rest of my family probably just found out about it and they probably think I`m completely mad. It`s probably right," Harry said.
The expedition to the North Pole was undertaken by a team of wounded British soldiers - who were injured fighting in Afghanistan. The team covered over 250 km in 12 days. Harry joined them in the early days of the walk - just before his brother William`s wedding.
He had spent some time preparing for the trek on the Norwegian island of Svalbard.
"My father was very nervous because of the lack of training that I`ve done and quite rightly so, he`s got a lot of friends who have done this, he`s got professional opinions that no doubt would have advised him saying `do not let your son go`."
The prince also reflects on his varying roles as a soldier and a royal.
"I think I have three different lives - one`s my military life, one`s my private life and one`s the sort of public stuff. But, you know, me as a military man is probably my number one favourite because you get to some time with people like this - it is very special."