capo di tutti capi
/ˈkapəʊ dɪ ˈtuːtɪ ˈkapɪ/originally US
noun
A person who runs every branch of the Mafia in a region.
Origin
1960s; earliest use found in Newsday. From Italian capo di tutti capi, lit. ‘boss of all bosses’ from capo + di of + tutti, plural of tutto all + capi, plural of capo.