I've planted bronze fennel in my herb garden and it's now taking over somewhat, can I move it to a better position in my garden, prune it and if so when?

It'll be disappearing soon anyway, as the season progresses! You can reduce the top growth by as much as you want - even to the ground, it'll still grow again next year. They are quite difficult to move - they have a very long root which is difficult to get out intact. If you spot any seedlings coming up anywhere, take those out and reposition them where you want them to grow, before they get large. You can give it a try though, but you know the best time for that is the autumn.

I haven't had luck moving them - both times I tried they didn't come back. Might be worth saving seeds so you can sow them exactly where you want to go. I had more luck moving sage in the past.

Bamboo is absolutely right about the tap root on Fennel. It is almost impossible to remove, let alone move a plant! If you let it seed, you will have loads of seedlings, some of which will probably be in the place you'd like them! OR collect seeds, of course, so you get to choose where they grow.

Make sure you heave out all the others, though, at a very early stage, as they will be the bane of your life, otherwise!