Origin of the "I before E except after C" rule?

I'm aware of the many exceptions. I'm looking for its origin, or earliest known documented use.

Origin of the "I before E except after C" rule?
Importantly, the full version of rule is as follows:


"I before E except after C, but only when the sound is EE".





The second part excludes many EI words (e.g. their, deign) because they aren't pronounced EE. There are still some exceptions though (e.g. weird, which is spelled weirdly!), but very few.





I don't know for sure, but I have often thought it came about from the English language's older Germanic roots.





In modern German, as far as I know, the sound of IE / EI is dictated by the second letter in the group. So in (modern) German, IE is pronounced EE and EI is pronounced I (rhymes with English 'eye').





To me, this links very strongly with the "only when the sound is EE" part of the rule.





Could the "except after C" part come about because those words come from another linguistic source where the pronunciation and spelling rules are different.? E.g. ceiling appears to have a Latin-based root.





As for the few exceptions (e.g. weird), perhaps their pronunciation has changed over time. Or perhaps they also reached the language from other sources.
Reply:Good answer, SV.


The exceptions are: seize, counterfeit, weird.