Both bands formed within a year of each other in the late 1970s, but did Cocteau Twins last as long as Pendragon?
Pendragon (band):  There were a few personnel changes in the early days, but since 1986 the lineup has remained relatively stable (with only the drummer changing twice since then) and the band is still active as of 2017, with a tour in October (Canada, NL, DE) and November (UK).
i don't know