Scarce Swallowtail in our garden

I planted a patch of Verbena bonariensi and Nicotiana sylvestris they attract winged things like a magnet, usually bees, boring cabbage whites and some red butterfly that are ten a penny here. We were in the garden after lunch, I noticed what I thought was a piece of paper then realised it was a huge white butterfly, (I later identified it as a Scarce Swallowtail) - I managed to catch it and put it in our special bug jar (one with a mesh top) whilst I ran and got my camera. We admired it and then took some pictures, and released it - sent it home to his mom for his lunch... according to T1.... I think we were lucky to have been visited as they are quite rare!