Career
Hiller was also an influential writer in the early German gay rights movement in the first two decades of the 20th century. In 1929, Hiller took over as chairman of the Scientific Humanitarian Committee from fellow gay activist Magnus Hirschfeld. From the end of 1933 to 1934, he spent time in a variety of concentration camps before fleeing to Prague later in 1934, and then to London in 1938.
In 1955, he returned to Germany, where he lived and wrote in Hamburg until his death.