Politics
Western Europe saw experiments with socialism with in governments and groups in Europe such as the Soviets and the UK. After the Vietnam war, socialist groups in Europe criticized the Soviet Union and social democracy. Forms of communism also spread in Europe driven by communist movements in the USSR and their satellite nations in Europe. Dictatorships in Germany, Italy, and other countries negatively impacted Europe in the first half of the 20th century. Constitutional monarchies were emerging. Strong rivalries between nations contributed to the two world wars.
Economic
Europe's economy had its ups and downs during the 20th century. As mercantilism emerged, the mass production of goods and global trade came to be. The economies of the countries directly involved were struggling during the two world wars, but began improving after the wars when other countries were pumping in money, supplies, and other goods to rebuild the nations that were impacted be the wars. A globally interconnected trade system was established and Europe's economy boomed.
Religion
Christianity was the most practiced religion in Europe during the 20th century. The Jews were persecuted by the Nazis during the 1930's-40's. Although the entire Jewish race wasn't destroyed, over 6 million Jews died in concentration/death camps during the Second World War. The persecution momentarily knocked the Jews out of Europe and there racism still continued. After the Second World War, religion was better tolerated in Europe.
Social
The persecution of Jews and other minorities was put in place by the Nazi party during the 1930's-1940's. Feminism rose as enlightenment ideas inspired women to rise up. During the wars, women worked in factories producing equipment and goods for their nation's military. Men remained above women. Government officials and rulers were appointed through meritocracy. The Aryan race claimed to be higher than everyone else.
Intellectual
The creation and mass production of new weapons were needed for both of the world wars and the Cold war. For example. never before seen tanks, air planes equipped to fight in the skies and more powerful naval fleets were created. Technology in general was a new intellectual achievement for the Europeans. The creation of nuclear power, nuclear weapons, and the internet was new as well.
Arts/Architecture
Uses for concrete and glass expanded in Europe during the 20th century. Concrete could be used to make buildings and bunkers. Modern, abstract, impressionism, and cube art came to be. Movies began to be played in Europe during the first half of the 20th century and soon spread outside of the continent.
Near Geography
Mountains and rivers created natural boundaries. The dense forests were used to hide military equipment and bunkers. The seas surrounding Europe created commerce and were the battle grounds for many battles.
Sources
http://media-cache-ec0.pinimg.com/736x/0b/65/fc/0b65fc68dad431433025ce9b2a822895.jpghttp://gdb.voanews.com/54D5373A-11DC-4F48-BFA3-D6B5404CFB3D_w640_r1_s.jpg
http://www.trunews.com/wp-content/uploads/2013/10/2_photo.jpg
http://schoolctr.hebisd.edu/education/page/download.php?fileinfo=d2VzdGVybmV1cm9wZS5wZGY6Ojovd3d3NS9zY2hvb2xzL3R4L2hlYmlzZC9pbWFnZXMvZG9jbWdyLzU4MzNmaWxlNTA3NjYucGRm§iondetailid=41143
http://i2.cdn.turner.com/cnn/dam/assets/131103110720-01-ebay-holocaust-1103-story-top.jpg
http://www.trunews.com/wp-content/uploads/2013/10/2_photo.jpg
http://schoolctr.hebisd.edu/education/page/download.php?fileinfo=d2VzdGVybmV1cm9wZS5wZGY6Ojovd3d3NS9zY2hvb2xzL3R4L2hlYmlzZC9pbWFnZXMvZG9jbWdyLzU4MzNmaWxlNTA3NjYucGRm§iondetailid=41143
http://i2.cdn.turner.com/cnn/dam/assets/131103110720-01-ebay-holocaust-1103-story-top.jpg