Tunneling to undermine walls probably began in the Bronze Age and it was used to breach trenches in WWI. It has apparently alway been awful work. I’ve read that

Tunneling to undermine walls probably began in the Bronze Age and it was used to breach trenches in WWI. It has apparently alway been awful work. I’ve read that some premodern walled cities sunk metal bars in pits below walls to try and find where enemies were digging.