The United Kingdom gives the first doses of the fully authorised Pfizer–BioNTech COVID-19 vaccine, beginning a global vaccination campaign.
The United Kingdom becomes the first country to leave the European Union, after 47 years of membership.
The World Health Organization declares the COVID-19 outbreak a global pandemic.
The Event Horizon Telescope collaboration releases the first direct image of a black hole, at the centre of the galaxy M87.
The James Webb Space Telescope, a NASA–ESA–CSA collaboration, is launched from French Guiana to observe the early universe in infrared.
Russia launches a full-scale military invasion of Ukraine, starting the largest war in Europe since the Second World War and displacing millions of people.
Queen Elizabeth II, the longest-reigning monarch in British history at over 70 years, dies at Balmoral Castle and is succeeded by Charles III.