into the French Empire. However, the later establishment of the United Kingdom of the Netherlands in 1815 marked a turning point. The end of the 19th century is sometimes called Amsterdam's second Golden Age. New museums, a railway station, and the were built; in this same time, the Industrial Revolution reached the city. The Amsterdam–Rhine Canal was dug to give Amsterdam a direct connection to the Rhine, and the North Sea Canal was dug to give the port a shorter connection to the North Sea. Both projects dramatically improved commerce with the rest of Europe and the world. In 1906, Joseph Conrad gave a brief description of Amsterdam as seen from the seaside, in The Mirror of the Sea. 20th century–present Shortly before the First World War, the city started to expand again, and new suburbs were built. Even though the Netherlands remained neutral in this war, Amsterdam suffered a food shortage, and heating fuel became scarce. The shortages sparked riots in which several people were killed. These riots are known as the Aardappeloproer (Potato rebellion). People started looting stores and warehouses in order to get supplies, mainly food. On 1 January 1921, after a flood in 1916, the depleted municipalities of Durgerdam, Holysloot, Zunderdorp and Schellingwoude, all lying north of Amsterdam, were, at their own request, annexed to the city. Between the wars, the city continued to expand, most notably to the west of the Jordaan district in the Frederik Hendrikbuurt and surrounding neighbourhoods. Nazi Germany invaded the Netherlands on 10 May 1940 and took control of the country. Some Amsterdam citizens sheltered Jews, thereby exposing themselves and their families to a high risk of being imprisoned or sent to concentration camps. More than 100,000 Dutch Jews were deported to Nazi concentration camps, of whom some 60,000 lived in Amsterdam. In response, the Dutch Communist Party organized the February strike attended by 300,000 people to protest against the raids. The most famous deportee was the young Jewish girl Anne Frank, who died in the Bergen-Belsen concentration camp. At the end of the Second World War, communication with the rest of the country broke down, and food and fuel became scarce. Many citizens traveled to the countryside to forage. Dogs, cats, raw sugar beets, and tulip bulbs—cooked to a pulp—were consumed to stay alive. Many trees in Amsterdam were cut down for fuel, and wood was taken from the houses,