The house I was born in was built in 1903 and had distemper in the walls, and I know for a fact it's still there, in the bedrooms, under the current wallpaper.
Those images look similar in some respects, with the grey-white lime mortar/plaster finish. I can't say I ever had any trouble wallpapering over that, or in any of the dozens of houses in the locality that I worked in over the years. Obviously, distemper is powdery, and somewhat flaky, but as long as the walls are sized there was never any adhesion issues.
That said, paints really don't adhere as well and after time will start to flake. This seems to be what has happened in this case and people have probably painted over it (maybe even with oil paint in some cases), just to seal the surface, before papering.
There are options to get good results but they will be time consuming and may not leave a good enough surface for just painting onto.
You can scrape off the thicker stuff, and anything else that isn't well adhered, sand back to a relatively flat surface, then seal with a stabilising solution suitable for use over distemper.
Another method is to remove all of the paint and any remaining distemper with lots of elbow grease and a few dozen nylon scouring/sanding pads with hot water.
The other method is to get a plasterer to skim it all but be warned, some spreads will want the loose stuff/ distemper removed beforehand so that they have no comeback if the plaster doesn't adhere properly.
If you don't want any, or all, of that hassle, I would be tempted to just scrape off the loose stuff, apply a coat of Zinsser Gardz or a suitable wallpaper size, and re-paper. Wallpaper doesn't look out of place in older houses and there are some pretty nice ones out there these days.
Those images look similar in some respects, with the grey-white lime mortar/plaster finish. I can't say I ever had any trouble wallpapering over that, or in any of the dozens of houses in the locality that I worked in over the years. Obviously, distemper is powdery, and somewhat flaky, but as long as the walls are sized there was never any adhesion issues.
That said, paints really don't adhere as well and after time will start to flake. This seems to be what has happened in this case and people have probably painted over it (maybe even with oil paint in some cases), just to seal the surface, before papering.
There are options to get good results but they will be time consuming and may not leave a good enough surface for just painting onto.
You can scrape off the thicker stuff, and anything else that isn't well adhered, sand back to a relatively flat surface, then seal with a stabilising solution suitable for use over distemper.
Another method is to remove all of the paint and any remaining distemper with lots of elbow grease and a few dozen nylon scouring/sanding pads with hot water.
The other method is to get a plasterer to skim it all but be warned, some spreads will want the loose stuff/ distemper removed beforehand so that they have no comeback if the plaster doesn't adhere properly.
If you don't want any, or all, of that hassle, I would be tempted to just scrape off the loose stuff, apply a coat of Zinsser Gardz or a suitable wallpaper size, and re-paper. Wallpaper doesn't look out of place in older houses and there are some pretty nice ones out there these days.