Holland Dozier Holland; the amazing song writing trio that wrote so many of those sixties Motown hits.
However they felt under rewarded at Motown and had to take Berry Gordy to task to get their fees. They left Motown and set up their own company’s, and the full story of that has probably been hidden in litigation none disclosure agreements: see The Dark Side Of Motown.
Some of their post Motown songs have made it into the Northern Soul scene – e.g.
Eloise Laws “Love Factory”
Wikipedia: Holland Dozier Holland