“The Hollywood Reporter” — I don’t remember exactly the first time I met Mr. de la Renta. But I do remember the first dress I borrowed from him: from spring 2000, it was look 67. I had been asked to do an event for Sex and the City — something for HBO and [then CEO] Mr. Bewkes. I remember seeing this dress in the collection and went through Pat Field, the costume designer on the show, to see if she could help me borrow it. And I remember the first time I was invited to Mr. de la Renta’s office and asked if he might build a dress for me for the 2000 Emmys. It turned out to be a pink dress with a feathered skirt that people had a lot of opinions about — mostly because I tied a big piece of tulle on my arm.

I can’t remember how I had the courage to be friends with him — he was so otherworldly in a way. I don’t know if he ever really watched Sex and the City, but I’m certain he was aware of the show because he made a dress for a scene later. Misha’s [Mikhail Baryshnikov] character gave Carrie an Oscar de la Renta dress as a gift; it was a huge deal for Carrie to wear an Oscar de la Renta dress. That was a wonderful confluence of events because Misha and Mr. de la Renta had spent lots of time together in the Dominican Republic and had houses near each other. We all were friends.

I wore countless beautiful dresses of his, dozens of them, fresh off the runway. It was always a momentous occasion in my life when he would build a dress for me — for the Emmys, the Met Ball, for my 40th birthday at the Plaza. When Fashion’s Night Out started happening in 2009, I spent all those nights with Mr. de la Renta in his store on Madison, and it was a real honor. The first year I got there, he said, “Let’s sing!” He loved singing, sang beautifully. He was a muscular singer; it was one of the things he most enjoyed. He sang with mariachi bands, he delighted in any opportunity to create a festive environment. We did show tunes one year, mariachi another year — he even serenaded me. On every Fashion’s Night Out, I had to be at Mr. de la Renta’s store when he was there — it was planned around his arrival and his exit.

With the amazing Met Ball gown this year, I was involved in every step. Initially, when Anna Wintour asked if I might co-chair the evening — which would honor the work of the late couturier Charles James — with Anna and Mr. de la Renta also as co-chairs, I immediately thought that I wanted to ask him to make me a dress. I always have a little hesitation about asking somebody that. It’s a huge amount of effort, time, talent and money, so I put off asking for a while. But I was sitting with Anna one day and she said, “Ask Oscar, of course ask him!” So I rang him that day and said, “Would you consider building something for me for the Met Ball?”

I had been thinking of ideas and researching all of Charles James. I pulled a huge amount of James images and put pieces together from different dresses. Then I met with Mr. de la Renta’s design team; I worked first with Rafael, his incredible tailor, whom I’ve known for years. They presented ideas to him, he rang me, we talked more, then I came to the office and we started draping. I told the team about colors I wanted to work with and said, “What I would really love to do is have his well-known signature in embroidery on the back of the dress in scarlet.” They love him so much there, they got really, really excited about that. I was nervous to ask him — I expected that he might be modest and say no, no, no. But he thought about it and said yes the next day.

We had three different sizes of the signature made; I picked the color I thought was right, and he and I agreed on the size. I promised him, if the concept was misunderstood, I wanted everyone to know this was my choice. It was something he never would have done — with his modesty, grace and elegance. But I knew the crimson signature would look magnificent on the red carpet. Then Mr. de la Renta added the black lattice work up the back of the gown — an homage to Charles James — and I said, “Oh my God, of course!” It was so Oscar de la Renta!

It was really, really fun and thrilling to wear that gown that night. The point of the signature, and doing it in scarlet instead of his traditional navy, was to honor him — to scream it from the rooftop without opening my mouth. This is a man who spent the last 50 years building dresses. He’s singular. And that night I wanted to say thank you and pay tribute to him and convey my gratitude for his work and for the personal relationship he allowed me to have with him.

When someone passes who’s led a wonderfully long life, you hear the news and immediately think of his beloved wife and friends and, in this case, all those who work in his studio. The reality of his absence means a momentous shift. There are wonderfully talented designers, emerging and upperclassmen, but he really was singular, and he has left a vacuum. Others will come along and will eventually make ball gowns with pockets in them — with stripes and polka dots, garden party gowns. But nobody is meant to fill the void. They can’t. All I can think today is, “That’s it. That’s done, that extraordinary moment in time that he created.” When I think about the last 10 or 15 years and the way he figured out how to marry his rock-hard foundation of the world of socialites and Nancy Reagans with a different generation — it’s wildly impressive.

The great news is, we all got so much out of knowing him. Thank goodness for all the time we did have. It’s nice not to have regret — “I wish I’d met him!” He gave so much, and I think everybody who had the chance to be on the receiving end appreciated him.

It also needs to be said that there was no one more handsome.

This story first appeared in the Oct. 31 issue of The Hollywood Reporter magazine.