Question about cars

So I got back to the long stay car park after a holiday and the car won't start. Turns out the missus left the interior light on. I had jump leads, so no issue it was going again in a few minutes thanks to a kind stranger. Then I had an hour's drive home so that was easily enough time to charge it up. Anyway the next day, the car won't start again, a dead battery. My question is could completely draining the battery 'break' it or has my alternator gone as well which would be a coincidence?

Ps sorry for the full thread haha