This entry can get really long if we do the etymology of all the variant forms here (the OED gets down to a zeta list of main groups of variants) but the basic point in the OED and Latham is that "emir of the sea" is a thing that existed but is somewhere between certainly and almost completely certainly a common folk etymology instead of actually related the popularization of the Sicilian title, with this bit only showing up in the translation of the first term without the definite article.
Note also that this is the only location Google knows of on the internet that thinks a "Gerard Allard of Winchelsea" existed and neither source seems to include him. It's possible that's a modernization (?) of an actual form (?) of a name in the first citation, though, since Google is only allowing me a snippet view of the work. Anyone who can verify that it isn't in there at all, kindly put the correct form or remove it as unsupported. Still not sure of original text involved or language but the guy exists. @Nbarth seems to have just written "Gerard Allard" for Gervase Alard for some reason (?). Unless it really was in English and the OED is wrong on its dating, though, it seems even the accurate guy isn't accurate. William de Leybourne is on record as the English admiral for a decade before; his title was definitely recorded in Latin though (Admirallus Maris Angliae). — LlywelynII 19:41, 20 April 2024 (UTC)
Previously we listed as a separate sense
It's completely valid to have a separate subsense for the kapudan pasha but (1) we should use "historical" instead of "obsolete" and "Ottoman naval ..." instead of "prince or Saracen ... under the Sultan" and (2), if we start listing all of the examples of translations that fall under sense 1, it's going to be a laundry list. My own feeling is we can leave this as an implicit bit of sense 1 for now. Separately, though, we probably need an entry for kapudan pasha as an English loanword. — LlywelynII 04:38, 20 April 2024 (UTC)