in 1870, and entered a period of stagnation. Serock experienced a sizeable influx of Jews as a result of Russian discriminatory policies and the expulsion of Jews from Russian lands (see Pale of Settlement), however, many soon emigrated to the Americas. In the early 20th century Serock was a popular destination for Polish artists. During World War I it was occupied by Germany, and in 1918 local Poles disarmed the Germans, and Serock was reintegrated with Poland, which just regained independence. The town rights were eventually restored in 1923. World War II In September 1939, Serock was a place of fighting between the Poles and the invading Germans during the Invasion of Poland, which started World War II. On September 5, 1939, around 50–70 people, both inhabitants of Serock and refugees from nearby Nasielsk, were killed in a German air raid. In mid-September 1939, the Einsatzgruppe V entered the town to commit atrocities against the population. Under German occupation, Serock was annexed directly to the Third Reich, and the boundary between the Third Reich and the General Government proceeded along the Narew river. In autumn of 1939 the Germans carried out massacres of around 150 Poles from Serock in the nearby forest as part of the Intelligenzaktion. In December 1939, around 3,000 Jews were expelled from the town by the Germans. In April and October 1940, the Germans carried out mass arrests of hundreds of local Poles, many of whom were deported to concentration camps, and in spring of 1940, another 50 Poles were murdered in the nearby forest. In 1940–1941, the Germans expelled hundreds of Poles, who were then held in a camp in Działdowo and deported to the Kraków region in the General Government, while their houses, shops and workshops were handed over to German colonists as part of the Lebensraum policy. From 1940 to 1944 there was a forced labor camp there, the prisoners of which were mostly Poles from Serock and nearby villages, some of whom were afterwards deported to forced labour elsewhere. The Germans destroyed the Jewish cemetery. The Polish resistance movement was active in the town, and secret Polish schooling continued. In February 1941, the Germans carried out an execution of 21 members of the Polish resistance movement. In 1942 the ghetto contained around 2,000 people. In October 1944 the Eastern Front ran through the town. Germany defended from Serock across the Narew against