I met Issy at a friend’s wedding in Salisbury Cathedral. I was standing outside when this extraordinary girl walked by. I told her I liked her hat. She told me she liked my jacket. My grandfather was a Sri Lankan ambassador and I was wearing one of his, trimmed with gold brocade. So the hat and coat got together, as it were, and we loved one another from that moment until last week, when Issy died.

I have been overwhelmed by all the tributes to her and Issy would have been thrilled to know how highly she was regarded. Geordie Greig, the editor of Tatler, said she “was without doubt one of the great figures of fashion in the 20th century”.

Issy always looked amazing, but inside she was very insecure and lacking in self-confidence. But no one had her judgment or her wonderful eye: she spotted the milliner Philip Treacy and the designer Alexander McQueen long before anyone else.

She saw the extraordinary beauty in models Sophie Dahl and Honor Fraser and Stella Tennant (though technically Plum Sykes, who was Issy’s assistant, found Stella – Issy had asked her to round up some beautiful society friends). It annoys me when people call Issy eccentric – to me that describes the sort of person who eats goldfish. She worked every day. She didn’t care a thing about turning up on time, but she never stopped thinking about her work and how to be creative.

I was entranced by her from the start. I invited her to dinner – she turned up in a silver skirt and a bandana with her little feet in Manolo Blahniks – then down to the country for the weekend. I had a girlfriend at the time who was jealous and looking daggers at me. In Gloucestershire we went for walks and Issy told me she loved the countryside.

The next day I rang her and said I was coming up to London to get my hair cut. When we met I told her: “I don’t want to have an affair with you, I want to marry you.” That was 16 days after we met. She said yes straight away.

People were amazed because though I was exotic and bohemian I was quite rural. The Blows’ glory days were gone and we were pretty much hillbillies. I said to Issy that I hardly ever got girlfriends and she said: “That’s because you don’t have a fast car and take cocaine.” But she didn’t seem to mind.

When I first met Issy my sense was, “Wow, you’ve got talent”. But she didn’t realise that. She hung around with a lot of beautiful people but they weren’t talented, they were rich. I saw myself as giving her a platform. So we set up home in London and she loved the idea of becoming a patroness.

My mother had a run-down house in Belgravia. Issy had met Philip Treacy around the same time as me and he was soon installed in the basement, followed later by Alexander McQueen. So she could do something to really help the people she believed in.

Philip was still a student at the Royal College of Art then and the first thing he showed her was a green felt hat with jagged, crocodile teeth edges. She wore his hats ever after, hats in the shape of lobsters or sailing ships.

She spotted Alexander McQueen in 1993. She went around championing him and people laughed, saying he made theatre clothes. But she knew how talented he was.

In 1996, when he got the job of head designer at Givenchy, she was delighted. We saw him after one of his Paris shows and she said: “I expect you’ve seen lots of people like me today,” and he said: “Issy, there’s no one like you.”

Issy went to work for Anna Wintour at Vogue. It made me laugh last week when Anna said she’d never been good at getting in before 11am, but then she’d turn up dressed as a maha-raja or an Edith Sitwell figure. But she was frustrated. You can’t really be creative working in an office. That’s what she really loved later on about working at The Sunday Times. Nobody expected to see her in the office, they wanted her out there, looking for talent.

Everything was going well for her at work but Issy wanted a child and when we tried, nothing happened. She went through IVF but it didn’t work. There was nothing wrong with Issy and nothing wrong with me. It just didn’t happen. She said we were like two exotic fruits who couldn’t breed.

So that was very hard for her. And she always carried a burden from her childhood. She was the granddaughter of Sir Jock Delves Broughton, who was acquitted of murdering the Earl of Erroll in the notorious White Mischief case. When she was four her two-year-old brother brother died in a freak accident.

It was a nice sunny afternoon, her mother was going upstairs to put lip-stick on, her father was laying out the drinks, people were coming round for drinks, and her brother fell into the swimming pool and drowned. It finished her parents’ marriage pretty much.

Later on when her mother walked out – when Issy was 14 – she shook Issy and her sister by the hand and said goodbye. When Issy died she hadn’t seen her mother for eight years. After she left, Issy’s stepmother arrived with her stepsisters and Issy was more or less told, “You’re out”. So she had a lot to deal with.

During her twenties she was super-insecure. I tried to give her confidence, but Issy had no love from her parents and that’s really difficult. I don’t have children, but I know they need love, the sort of love I had from my parents. So that was the root of her depression later on. It’s no secret that she tried to kill herself with pills and car crashes and jumping off bridges.

She once called the National Trust and found out where Virginia Woolf’s house was, intending to end her life there. She rang them up and they said the river didn’t have any water in it. So having failed to do a Virginia Woolf, she tried to do an Anna Karenina. It was difficult to live with, but I loved her and I was well trained: my father suffered depression and killed himself when I was 13. Very talented people often suffer problems. It’s the price one pays.

Then last year she was diagnosed with ovarian cancer. I’d guessed something was wrong and brought her down to the country. When the blood tests came back they were inconclusive, but when they opened her up she was riddled with it.

Last Saturday I brought her downstairs where she could look out onto the fields. On Sunday she took a turn for the worse. She said: “I love you,” but there was no great speech. She was fighting for breath. She knew she wanted to die and it seems she helped things along [preliminary toxicology reports suggest she drank Paraquat, the weedkiller].

My life will go on, but in a way I can’t imagine: I’ve become addicted to drama. Issy will stay in everyone’s memory. I sent my business partner a message saying she had died. He texted back: “Long live Queen Isabella.”

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