I agree with Sweeney, looks like manila, and not in too bad of shape that it would need to be replaced. It looks like there is enough length that you could get an eye splice in the frayed end, and have good rope in the eye. Do you know how the frayed end was finished before it was frayed? Some flagpole systems utilize hooks on the halyard that are connected to grommets on the flag. It looks like this flag may have been adapted to be flown with this rope header. It probably has an interesting story.
interesting points, thanks PatD,
i'll have to start asking the rellys more questions about its story
(prior to me packing it away)
um, splices, i've never done them but yous think it can be salvaged,
which is good news to me,
no idea of the finish of it before fraying,
i thought it'd be symmetrical to the other end,
but evidently i have no clue,
i will formulate my further questions,
or ... great if you have a pic of existing finish of same
i haven't got anything to compare it to!,
i'll have a look on the internet