Brilliant, thank you both. I'm a little concerned - RED Interior Design - that three may distract from our antique lights over the fireplace. I've attached a little more of the room for you to see. There's a lot going on, what with the kitchen light in the background and the funky blue tiles around the fire! Should I just stick with one larger one?

I'd say depends on the size of the pendant. If you're going for the smaller end of the market - a lot average out at around 22cm across, then you could get three in that would be roughly from edge to edge - gap 28cm - light 22cm - gap 29cm -light 22cm - gap 29cm - light 22cm and finally gap 28cm If you fancy something bigger than 22cm then i'd probably stick to two lights - after all you don't want to be too close to peoples heads - This one is based on 35cm shades - Gap 37cm - light 35cm - gap 36cm - light 35cm - gap 37cm

I forgot to ask the chain length... it’s really quite tricky finding something, you’d hope something would just come up on a search for vaulted ceilings! I don’t know what you think of this. It can go on a sloped ceiling, max drop is 2.36m and it’s 1.4m wide so should light the whole table. I know it’s mid century in style but I think works with the slightly industrial table and other lights (especially if you stick with the round bulbs for both)

One of my friends had a similar situation in his old house and normally the lighting being off centre would bug me just because I like the symmetry. However what he did was to position them so they were centred over his dining table instead which was in a similar position to where your green square is and it looked great. The fact they were in context with the furniture made the fact they weren't centred in the room a complete non-issue.