Williams had only lost the first set 6-2 in five previous Grand Slam finals, with the results all following the same win-loss pattern - but that record was broken on Centre Court on Saturday.
On the day, Williams, who was chasing her 24th grand slam win, was relegated to the role of bit-part actor as Halep produced an extraordinary performance.
Halep fell on her knees with arms raised to the sky in celebration.
King had mentioned in June that she'd like the 23-time Grand Slam victor to cast aside her other efforts and give what's remaining of her tennis career her all so she can have no regrets when she calls it a day.
Serena Williams' tennis career will come to an end one day but her determination to fight for equality won't.
"It was the best match I have ever played", Halep said.
In her fifth showpiece final, Halep demolished the 23-time major victor Williams 6-2, 6-2 in 55 minutes on Centre Court but before then came some hardships.
'Ilie, thank you for coming, you're supporting me all match, ' she said for good measure.
"It was my mum's dream".
Serena Williams delivered a stinging rebuke to fellow tennis legend Billie Jean King who said she should focus on tennis and stop behaving like a celebrity and fighting for equality.
Following her comments, King took to Twitter to clarify what she meant when she called on Williams to focus on tennis.
"In the meantime, I got pregnant, had a baby, so. that definitely plays a little bit into it". I should just focus on my game. I don't know what she wants.
The Wimbledon championships are hosted by one of the world's most exclusive tennis clubs and winning a title confers lifetime membership.
"She was crying", said Halep when asked what her mother's reaction was. She spoke after her semifinal victory about trying to remain calm on court, and that she did, even in the face of a player who was at her very best. So today it's real and I'm really happy.
"Now, you know, in my 20s - I'm always expected to win, but it's a different circumstance for me", she said. It was an awesome tournament and I can't wait to come back. I just went for it.
Serena Williams is being praised for her response to a question about whether she should stop focusing on equality and start focusing more on tennis.
Nevertheless, Williams refused to accept that the record may elude her.