Simon Cowell, 65, and Liam Paynes ex Cheryl, 41, came together at the funeral on Wednesday.
The service for Liam, who passed away on October 16 at the young age of 31, was held in Amersham.
It was a touching ceremony hosted by his family and attended by all his loved ones.
Despite past disagreements, Cheryl and Simon both attended the funeral, united by their strong personal connections to the former One Direction star.
There was a time when Cheryl and Simon didnt speak for years due to a severe disagreement that led to a significant feud.
Their most notable fallout occurred in 2011 when Cheryl was dismissed from X Factor USA just weeks into her job, before the show even aired.
After splitting from Ashley Cole, Cheryl moved to the US, but Simon let her go after she seemed too overwhelmed to fulfill her role.
My falling-out with Cheryl came soon after her divorce and was a nightmare, Simon confessed to Radio Times in 2014.
Liam Payne and Cheryl broke up in 2018
We were all wound up. There was so much expectation on the show in America and I definitely wasnt myself. I was uptight.
He later criticized her appearance, claiming she wasnt the woman he once knew.
When I saw her I didnt recognize her, he said, adding, Literally. The hair and outfit were crazy. Just totally crazy. I asked her manager, Whats she wearing, whats happened to her hair?
He continued: He was defensive about it. I havent a clue why she turned up like that. Shed put on a bit of weight, but not loads. That wasnt the issue. The only way I can describe it is that it wasnt Cheryl sitting in that seat. Shed lost her confidence.
Cheryl went on to send Simon a horrible text, and she later admitted: In hindsight, he was right because I wasnt myself. He wasnt himself either. He was under a lot of strain because it was a new venture. But he handled it wrongly he got somebody else to sack me.
I didnt want to talk to him at the time. I didnt want to talk to anybody. The sacking came on top of everything else, it was just the cherry on the cake.
Cheryl and Simon then reportedly went years without speaking, with their relationship seeming to be over for good.