At 3.17am I was sitting at my desk when I started feeling a bit giddy. After a few secs I suspected it might be an earthquake. Turned round to check the chandelier light fitting in the dining area and sure enough it was swaying. As was a window blind cord. Nothing more than that: no shuddering. Went on for about 20 secs.
Just checked an eathquake monitoring site
https://earthquake.usgs.gov/earthquakes/map/?currentFeatureId=us6000jlm1&extent=-22.43134,0.52734&extent=62.59334,82.44141 and it seems there was quite a large earthquake in Turkey, about 500 km away. 7.8 on the Richter scale, which I believe is very high. And a further one of 6.7 at 3.28, which I think I felt also.