My great-grandmother, Bertha, died in 1978. Her father died in 1911. I posted a picture of his tombstone , engraved almost entirely in Hebrew, a month ago.
I was 9 when she passed away, and I remember her vaguely, but only in her later years confined to a wheelchair at a retirement home. My father and uncle tell stories about her, and one they've told often is how she always referred to her father, and insisted everyone else do the same. Whenever you invoked his Hebrew name, Moshe Leyb, you were always supposed to follow it with, "the King". She never explained why. (Outside the family, he used the Americanized name, Morris.)
One might guess that it had something to do with family politics. Though it wasn't clear whether it was completely out of respect for someone who was the 'head' of the family, or whether there was a little poking fun at someone who wasn't always. We left it as a quirky inside joke we would probably never understand completely.
And then I found his tombstone, and discovered the answer was written on it. While my generation and my parent's generation know Hebrew characters enough to follow along in the prayer book during services, and we have a small vocabulary, we don't think in Hebrew. And his surname was Cruvant, which begins with a C, so in English it's not readily apparent.
If you know Hebrew well, you probably already realize what I finally realized, but since most of you probably don't, I'll spell it out. My great-great grandfather's initials in Hebrew were: מ ל ק (MLK), which is Hebrew for King.
The exact family politics behind the joke is still obscure, but it's clear how the epithet arose.