The leaf reminds me of a Ceanothus.

Thanks. Actually maybe I haven't photographed the leaf in enough detail. Would it help if I took a close-up photograph of the leaf?

I'd say definitely a type of Ceanothus.

Ok thanks. close-up picture of leaf added.

It doesn't look at all like my ceanothus - perhaps different varieties have different shaped leaves?

Thanks. It's a bit of a mystery then? Is my picture of the leaf not detailed enough, do you think?

Does it have blue flowers? Or does it have prickles?

Thanks to above. Update on this, it presently has these blue-purple flowers as shown in the 3rd picture added to the original question.

Definitely a Ceanothus.