Ballaghmor Class, one of the greatest horses in eventing history, will be officially retired at Burghley on Sunday

Ballaghmor Class's stunning Burghley victory in 2017 was achieved on the horse's CCI5* debut - he subsequently recorded a remarkable 10 consecutive top-five finishes at CCI5* level and delivered 13 clear cross-country rounds in a row - highlighting his iconic status.

Here, Oliver recalls that special Burghley triumph of nine years ago, speaking with Andrew Baldock.

"I don't know what had clicked in my mind, but I came out of the dressage at Burnham Market in the spring of 2017 and just had a feeling that we would go to Burghley on him that year. That was basically where it started. He had given me a feeling in the dressage that we weren't going to be far off competitive, and for me, the cross-country department had clicked in to be his major strength.

"I was quietly very confident. I felt like I was going with a secret, it was weird! He was still babyish on the flat. Flying changes were not established at all, and I remember being out in the warm-up at Burghley still continuing his education and still training flying changes. It sounds mad. I think there were four flying changes in the test at the time, and I thought if we got four, then we could win this.

"I thought if we finish in the top six after dressage, then we could win. We were sixth after dressage, and I thought 'we are on'.

"I let him warm into the cross-country course a little bit. He has got a huge amount of stride, so I was very conscious of not setting off fast. He was partly in control a lot of the time! I felt my way around the first part of the course.

"I remember watching the replay. Ian Stark and Andrew Nicholson were commentating with Nick Luck. I like all three men. Two of them have been my heroes, and I am a big racing fan, and Nick is fantastic at his job. They were discussing whether I could go clear or go inside the time, and my supposed best mate Andrew Nicholson said: 'Realistically, no'! As they are watching the round unfold, you can hear them quietly changing their opinions!

"I got to about halfway, pressed the go button and the response was like something I had probably not felt. It was the difference between driving a nice car and a Formula One car. The stride length, everything just became a bit of a whirlwind.

"It was one of those wow moments. I had gone into shock. We were one second over the time, but that one second was probably me trying not to get carried away. Once I had opened him up, I was always feeling like 'whoa, whoa, whoa' all the way back. If you are doing that at the fences at Burghley then you have definitely got something that is going underneath you.

"It was tight at the top going into the jumping, but the horse in front of me had a fence down, which allowed me to have a fence. It wasn't a given by any means, but I said to Ian Stark before I went in that whatever happens today, I think it is one of the best horses I've had.

"I was so focused and in tunnel vision on the cross-country that you don't get to enjoy it until it's over, and then you can't believe it for so long. It had been a long period of time (eight years) between five-star wins. I have been lucky enough to win nine, but my first two came very early in my career and it's a bit like 'is that going to be it'? Then all of a sudden it happens again at one of your favourite five-stars in the world, the most difficult five-star in the world to win. I don't think I have ever watched a round on replay as much as I have watched that round.

"Burghley is part of me. I first went there as a two-year-old when my dad competed as an amateur in 1984. It is something that has been a very important part of my life, the most special event you can win."