The camp was established in 1936. It was located north of Berlin, which gave it a primary position among the German concentration camps: the administrative centre of all concentration camps was located in Oranienburg, and Sachsenhausen became a training centre for Schutzstaffel (SS) officers (who would often be sent to oversee other camps afterwards). Executions took place at Sachsenhausen, especially those that were Soviet Prisoners of War. Some Jews were executed at Sachsenhausen and many died there, the Jewish inmates of the camp were relocated to Auschwitz in 1942. Sachsenhausen was not intended as an extermination camp — instead, the systematic mass murder of Jews was conducted in camps to the east. However, many died as a result of executions, casual brutality and the poor living conditions and treatment.
Sachsenhausen was intended to set a standard for other concentration camps, both in its design and the treatment of prisoners. The camp perimeter is, approximately, an equilateral triangle with a semi circular roll call area centred on the main entrance gate in the side running northeast to southwest. Barrack huts lay beyond the roll call area, radiating from the gate. The layout was intended to allow the machine gun post in the entrance gate to dominate the camp but in practice it was necessary to add additional watchtowers to the perimeter.
The standard barrack layout was two accommodation areas linked by common storage, washing and storage areas. Heating was minimal. Each day, time to get up, wash, use the toilet and eat was very limited in the crowded facilities.
There was an infirmary inside the southern angle of the perimeter and a camp prison within the eastern angle. There was also a camp kitchen and a camp laundry. The camp's capacity became inadequate and the camp was extended in 1938 by a new rectangular area (the "small camp") north east of the entrance gate and the perimeter wall was altered to enclose it. There was an additional area (sonder lager) outside the main camp perimeter to the north; this was built in 1941 for special prisoners that the regime wished to isolate.
An industrial area, outside the western camp perimeter, contained SS workshops in which prisoners were forced to work; those unable to work had to stand to attention for the duration of the working day. Heinkel, the aircraft manufacturer, was a major user of Sachsenhausen labour, using between 6000 and 8000 prisoners on their He 177 bomber. Although official German reports claimed "The prisoners are working without fault", some of these aircraft crashed unexpectedly around Stalingrad and it's suspected that prisoners had sabotaged them.  Other firms included AEG.
Plaque to honour over 100 Dutch resistance fighters executed at Sachsenhausen.Later, part of the industrial area was used for "Station Z", where executions took place and a new crematorium was built, when the first camp crematorium could no longer cope with the number of corpses. The executions were done in a trench, either by shooting or by hanging. Amongst those executed were the commandos from Operation Musketoon and the Grand Prix motor racing champion, William Grover-Williams, also John Godwin RNVR, a British Naval Sub-Lieutenant who managed to shoot dead the commander of his execution party, for which he was mentioned in despatches posthumously. Over 100 Dutch resistance fighters were executed at Sachsenhausen.
The camp was secure and there were few successful escapes. The perimeter consisted of a three metre high wall on the outside. Within that there was a path used by guards and dogs; it was bordered on the inside by a lethal electric fence; inside that was a "death strip" forbidden to the prisoners. Any prisoner venturing onto the "death strip" would be shot by the guards without warning.
Arbeit Macht Frei gateOn the front entrance gates to Sachsenhausen is the infamous slogan Arbeit Macht Frei (German: "Work Makes [You] Free"). About 200,000 people passed through Sachsenhausen between 1936 and 1945. Some 100,000 inmates died there from exhaustion, disease, malnutrition or pneumonia from the freezing winter cold. Many were executed or died as the result of brutal medical experimentation. According to an article published on December 13, 2001 in The New York Times, "In the early years of the war the SS practiced methods of mass killing there that were later used in the Nazi death camps. Of the roughly 30,000 wartime victims at Sachsenhausen, most were Russian prisoners of war, among them Joseph Stalin's eldest son (Yakov Dzhugashvili).
The wife and children of Rupprecht, Crown Prince of Bavaria, members of the Wittelsbach family, were held in the camp from October 1944 to April 1945, before being transferred to the Dachau concentration camp. Reverend Martin Niemöller, a critic of the Nazis and author of the poem First they came..., was also a prisoner at the camp. Herschel Grynszpan, whose act of assassination was used by Joseph Goebbels to initiate the Kristallnacht pogrom, was moved in and out of Sachshausen since his capture on the 18th July 1940 and until September 1940 when he was moved to Magdeburg. Ukrainian nationalist leader Stepan Bandera was imprisoned there until October 1944, and two of his brothers died there.
On September 15 1939, August Dickman, a German Jehovah's Witness, was publicly shot as a result of his conscientious objection to joining the armed forces. The SS had expected his death to persuade fellow Witnesses to abandon their own refusals and to show rspect for camp rules and authorities. It failed; the others enthusiastically refused to back down and begged to be martyred also. 
Sachsenhausen was the site of the largest counterfeiting operation ever. The Nazis forced Jewish artisans to produce forged American and British currency, as part of a plan to undermine the British and United States' economies, courtesy of Sicherheitsdienst (SD) chief Reinhard Heydrich. Over one billion pounds in counterfeited banknotes was recovered. The Germans introduced fake British £5, £10, £20 and £50 notes into circulation in 1943: the Bank of England never found them. Today, these notes are considered very valuable by collectors.
Many women were among the inmates of Sachsenhausen and its subcamps. According to SS files, more than 2,000 women lived in Sachsenhausen, guarded by female SS staff (Aufseherin). Camp records show that there was one male SS soldier for every ten inmates and for every ten male SS there was a woman SS. Several subcamps for women were established in Berlin, including in Neukolln.
Camp punishments could be harsh. Some would be required to assume the "Sachsenhausen salute" where a prisoner would squat with his arms outstretched in front. There was a marching strip around the perimeter of the roll call ground, where prisoners had to march over a variety of surfaces, to test military footwear; between 25 and 40 kilometres were covered each day. Prisoners assigned to the camp prison would be kept in isolation on poor rations and some would be suspended from posts by their wrists tied behind their backs (strappado). In cases such as attempted escape, there would a public hanging in front of the assembled prisoners.
With the advance of the Red Army in the spring of 1945, Sachsenhausen was prepared for evacuation. On April 20–21, the camp's SS staff ordered 33,000 inmates on a forced march westward. Most of the prisoners were physically exhausted and thousands did not survive this death march; those who collapsed en route were shot by the SS. On April 22, 1945, the camp's remaining 3,000 inmates, including 1,400 women were liberated by the Red Army and Polish 2nd Infantry Division of Ludowe Wojsko Polskie.
It's estimated that 200,000 people passed thrugh Sachsenhausen concentration camp and that 100,000 died.