Large flying insect identification

Just trying to identify an insect I saw last night, I was passing the entrance to our little village in the countryside and collecting our mail delivered to the post boxes their, when a large (seemed between a golf ball and tennis ball sized) flying insect came and buzzed around me. It was hard to see but seemed to be black, with hard wings like a beetle and was obviously nocturnal as it was attracted to the lights. I don't think it was a Bat but I have never seen such a large flying insect before and wondered if anyone knew what it might be. It made a loud buzzing sound. I have lived their for a number of years and never seen anything like it, we have large carpenter bees and wasp but this was much bigger. two ore three times the size.