Who was Jacques de Bascher?

I was never familiar with Jacques de Bascher. I just recently found out he was the late Karl Lagerfeld’s boyfriend, although they never had sex together because Karl was a puritan and he had a very clean life. That is why I am curious what really killed him, even though he was 85 years old. I remember hearing in a video that he used to drink a lot of Diet Coke, in which I think is a toxic drink. So, who knows.

Anyway, now Karl has been cremated and placed with his late mother and late boyfriend. I wonder if his late father is with them as well. He never really spoke about his father.