From The Last of the Name by Charles McGlinchey about late late 19th century life in Northwest Ireland. "Most houses had a half-door as well as an ordinary one. Yhe door was fastened inside by a wooden bolt; and on the outside, if the people were were going away for a day, it was locked with a padlock, a hasp and staple, that you got for a shilling. There was a latch, too, on most houses, a home-made wooden one or an iron one that you bought. The houses were hardly ever bolted at night, just left on the latch. A beggar could get a bed of straw beside the fire in nearly any house in the parish in those days."

So, this is a little late in history one a century and a half or so, but people used homemade bolts and latches and only had an iron lock for longer trips away. Now Charles lived in a very rural area, but notes that most people simply did not lock their house most of the time. This is one example, I had on hand about this. I hope someone else can give a more thorough history on locks and their development.

In the South of Germany, there are the remains of a big IronAge settlement near todays "Manching" The settlement was large and organised enough to be considered a town.

The settlement was left around 50 BC, shortly before the Romans came. Today, there is a archaeological museum the "KeltenRömer Museum Manching, which focuses on the excavation in and around that area. Part of the museu is a reconstruction of a house, featuring a sturdy wooden door with a wooden latch, which had to be turned and twisted to close and lock the door. If I remember correctly some parts of the excavation finds were waterlogged and could survive.

A short summary for the exhibition can be found here: https://www.museum-manching.de/index.php?id=0,49

Publications to archaeological aevidence in and around Manching is ongoing, but in German. (List is here: https://zenon.dainst.org/Search/Results?lookfor=daireih8ausgrmanching&type=LocalNote&x=23&y=6)