One other explanation of the historical context could be when Hitler and the Nazis controlled Europe when the Nazi "Final Solution" premise became more apparent. The Franks are hiding from 1942- 1944. At this time, the Nazis and Germany, as a whole, experienced a change in the momentum in the war. At the time of 1942, there was some serious doubt as to whether the Allied Powers could defeat the Axis powers. Throughout the diary in the context of the war, the Allied powers were able to assert their power and change the momentum. As the war became increasingly unwinnable for the Germans, Hitler's advancing of "the Final Solution" moved from philosophical goal to expedient reality. This meant the finding and exterminating of "enemies of the Reich," and in particular Jewish people, became a need for the Nazis. This context makes its way in the diary as Anne reflects both the joys of hearing about Allied victories with the fear of what will come next, as the Nazis were clearly not willing to surrender their control without an extremely tenacious fight in the process.
On a more localized level, you can also say the historical context of Anne Frank's story is wartime occupied Holland (The Netherlands). The country fell in less than a week to German armies in 1940, so those Jews who were in the country at the time, either as refugees or citizens, were immediately trapped.
You can also say the historical context of the book is anti-semitism, or anti-Jewish attitudes among the general public. Jews had long been the scapegoat for Europe's economic and social problems, and the anti-semitism in wartime Holland led to Anne's eventual discovery and the murder of her and her family.
The historical context of this work is World War II and the Holocaust. Anne Frank was a German Jewish girl whose family fled from the beginnings of Nazi anti-Jewish laws. As anti-Jewish sentiment in Germany grew, they fled to Amsterdam.
Unfortunately for the Frank family, Germany easily overran all of Western Europe once the war started in 1939. Therefore, the Franks were once again under Nazi rule. They started hiding in a secret part of the home of a friend so as to avoid being sent to the death camps.
Late in 1944, the Franks were found out. Anne herself died in early 1945. Only her father survived the Holocaust.