Green’s Dictionary of Slang

(orig. US, also KP) the central figure, the most important figure in an organization or team.

1865		H.L. Williams Joaquin 60: I called myself [...] a red-ball of villainy, a king-pin of wickedness, a knave of the pack of thieves.
1887		World (N.Y.) 26 Aug. 6/4: In the language of that eminent authority Mr. De Wolf Hopper, ‘Mickey Welch is a dandy and the king-pin of them all’.
1898		Kipling Fleet in Being vi. 76: The newer generation [...] know that he is the king-pin of their system.
1907		N.-Y. American 18 Dec. in Fleming Unforgettable Season (1981) 9: He is kingpin of the staff.
1916		Truth (Wellington) 15 Apr. 5/1: Lord Headly [...] a ‘king pin’ in the bakery and confectionary trades.
1926		K.S. Prichard Working Bullocks 258: ‘My!’ Mary Ann gasped incredulously, ‘and you was the king pin last week, Mark.’.
1935		S. Horler London’s Und. 57: A blackmailer. Of the highest possible type, of course — a top-notcher, a king-pin, a crackajack, an ace.
1941		V. Davis Phenomena in Crime 155: They have registered a conviction against the King-Pin of the ‘fences’.
1952		W.R. Burnett Little Men, Big World 46: [They] handled considerable underworld business, particularly the business of the ‘king pin,’ Leon Sollas.
1960		C. Cooper Jr Scene (1996) 26: Knock out this kingpin, the fella you call The Man.
1973		A. Salkey ‘Saturday in Kingston’ Jamaica (1983) 61: King-pin Boysie Smart / cupped his prick and balls / and shuffled proudly up.
1975		D. Goines Inner City Hoodlum 42: No-one enjoyed giving the tall black kingpin information that was bad.
1988		Ice-T ‘I’m Your Pusher’ 🎵 I’m the king pin when the wax spins.
1998		Source Oct. 154: The convicted kingpin of one of the city’s most violent crack cocaine gangs.
1999		D. Looser ‘Boob Jargon’ in NZEJ 13 32: KP n. Short for King Pin - a leader who has gained his/her position from violence.
2000		G. Pelecanos Shame the Devil 121: I’ve heard that both [...] sold drugs. But if they did, it was minor. Neither of them was the kingpin down here.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 100/2: king pin n. 1a leader who has gained his position from violence or force.
2008		R. Price Lush Life 26: You gonna go all kingpin out there?
2011		IOL News (Western Cape) 9 May 🌐 The suspected bank robbery kingpin is still on the run.
2012		‘Dutch’ ? (Pronounced Que) [ebook] I hate a snitch, especially when a so-called kingpin rat out his family.
2017		IOL (Cape Town) 10 Sept. 🌐 Police arrested two people at the funeral of Durban’s alleged hijacking kningpin.
2020		(con. 1991-94) W. Boyle City of Margins 51: He trailed this drug kingpin’s mistress.