Katherine Chancellor (Jeanne Cooper), the owner of Chancellor Industries, was a mighty businesswoman.
Katherine came to appreciate Jill’s company and hired her as her assistant.
However, Jill’s being in close proximity to Phillip was not good for her and Katherine’s friendship.

Jill started to develop feelings for Phillip, and the two had an affair.
Despite her feelings for Phillip, Jill ended up marrying Brock.
The unexpected pregnancy was the beginning of the decades-long feud between Katherine and Jill.

When she picked him up from the airport, Katherine Chancellor tried to convince him not to marry her.
Phillip was mortally wounded, and Jill married him on his deathbed.
Their baby was eventually born, and Jill named him Phillip Chancellor III.

Katherine could not forgive this decision and offered Jill $1M for the child, but she refused.
She promised him she’d fund his salon if he stayed married to her for a year.
Later, when Katherine was presumed dead, Derek finally married Jill and expected to inherit Chancellor Industries.
When Katherine was replaced with an imposter, Jill took advantage and married Rex.
The real Katherine eventually returned and put the kibosh on their relationship because she was still married to Rex.
Jill found evidence that Phillip left it to her.
Katherine moved out because of the fighting, which drove her to drink after 20 years of sobriety.
Jill felt bad, and the two women eventually patched things up (viaSoaps in Depth).
Katherine made Jill CEO of Jabot Cosmetics, and peace reigned.
AlthoughKatherine Chancellor was killed offwhen Jeanne Cooper died, the legacy of her feud with Jill will live on.