It was also a month that, on Earth at least, was characterised by great commercial activity, in the form of after-Christmas sales to clear out the wares of now out-of-season goods. The Eighth Doctor once offered to take Sam Jones back to Earth in time for these sales. (PROSE: Genocide)
In 1918, January was the month in which rationing of sugar began in Britain during World War I. Some people, like Constable Albert Briggs, therefore regarded January 1918 as the first time they really understood the deprivations of war. (PROSE: Casualties of War)
In 1933, Weimar Germany entered its closing days, with the Nazi Party gaining electoral support amidst ongoing economic woes. (AUDIO: The Alchemists) Adolf Hitler became Chancellor of Germany on 30 January. (AUDIO: Neverland)
In 1936, Emil Hartung won the Cairo 500 with the help of the Seventh Doctor and Melanie Bush. When talking in the hotel later that night, the Doctor accidentally let slip some anachronistic information relating to radar technology. Hartung thereafter withdrew from public life and returned to Germany to aid in the development of the Luftwaffe, applying his newfound knowledge to the Hartung Project. This somewhat altered the history of the coming war, forcing the Doctor to later mitigate the effects. (PROSE: Just War)
In 1942, Nazis in France forced Pierre Vedrun to developed a transmat machine which they hoped to use to invade England. The Third Doctor and Marcel Sangenez's French Resistance cell fought to prevent such technology falling into the Nazis' hands. (COMIC: Timebenders)
In 1943, as the North Africa Campaign neared its conclusion, the Eighth Doctor was arrested in Sierra Leone for trying to sneak across the border without a passport. While in custody, he met with Graham Greene to inquire about the Markebo indicent before Greene returned to England.
In 1945, the Eighth Doctor, Greene and Alan Turing were based in Paris while attempting to crack a mysterious code. The Doctor and Turing fled to Germany when the Doctor was accused of murdering a woman named Daria on 31 January. (PROSE: The Turing Test)