Prior to alarm clocks being both reliable and commonplace in British society, there was an entire profession dedicated to waking people up each day.
Called “knocker-uppers”, these people would go through the streets of the town and wake people up to go to work - especially in the northern mill towns where people would work in shifts, and where getting up at sunrise was not necessarily the most time-appropriate.
Most would have used long poles (often made of bamboo) and tap on bedroom windows to wake the inhabitants, though there are documented cases of others using soft hammers on the walls, wooden rattles and even pea-shooters. Some would knock three or four times and move on, others would wait until the clients showed themselves to avoid any dispute over whether the client was awake.
The practice would mostly be phased out by the 1950s as alarm clocks started to be more reliable, but the role did continue in some industrial areas until the 1970s.