When did the valediction 'best regards' come into use?

In a letter from Queen Elizabeth I, dated 1601, there's the valediction "Your Sovereigne that best regards you." I doubt that this is the first appearance of the phrase "best regards" (and actually, here it's an adverb + verb, whereas as used nowadays it's more of an adjective + noun); but at least it probably means that "best regards," as an ending for a letter, probably started out something like that and was later clipped.

I think 'Regards' means 'I send you MY regards', rather than 'give somebody else my regards'. 'Best Regards' would presumably mean you wish to convey an even warmer sentiment. As I read on another thread today, I'd agree that the regards in question are probably the mildest and blandest good wishes you could offer someone.

[However, personally I hate it, since it often feels entirely insincere and said with out a thought.]