Si wrote in message
I've been given some red chillies that were dried over 40 years ago; is
there any chance the seeds will germinate if planted?

Seeing as some seeds found in a Pharaoh's Tomb were germinated I don't see
why not, give it a go but don't expect 100% or even 50% germination and it
might take a bit longer than normal.
Could even be a "lost" variety.

If there's an outside chance that they would germinate what would be the
best conditions for them and how would I start them (a good soak first
perhaps?). I have a nice warm airing cupboard if they want it, and a
small,
could-be-heated greenhouse.

Same as for normal chillies except I would expect staggered germination so
perhaps instead ofplanting them as normal spread them on wet kitchen paper
in a tub and place that in the airing cupboard. Check daily and when you see
roots then transfer that seedling(?) to a tray of compost, might need
tweezers.
This should be kept as near 70°F as possible, gradually reducing the temp,
but never going below 50°F. Need as much light as possible.
Keep in a greenhouse as per Tomatoes or plant out early June in a sunny
protected place.

Good luck, keep us informed.
--
Bob

www.pooleygreengrowers.org.uk/ about an Allotment site in
Runnymede fighting for it's existence.