Germanic. It's Burgfrieden in German, original meaning: peace among individuals enforced inside and under the 'jurisdiction' of a castle. I guess this must have existed in English as well, but maybe died out of use for lack of 19th century or WWI-era re-use; afew? *Lunatic*, n. One whose delusions are out of fashion.
There are heaps of compounds with this, among which
burgfolc townsfolk burggemót town meeting (moot) burgwaran/s burghers
The equivalent of fred/fried was frið, but this one went out of use, replaced by the French borrowing "peace", some time in the Middle English period.
I can't find an example of burgfrið.
OTOH, there are also lots of OE frið compounds, of which the prettiest is friðcandel: "peace candle" -- the sun.
