The Society of Authors ZAiKS, established 1918, was for many years the sole legal Polish copyright collective, and has remained the dominant one, following the loss of its de facto government-granted monopoly in 1995 as a result of entry into force of the new copyright law of Poland. It is a member of BIEM, CISAC and GESAC. Its headquarters are located in Warsaw at the ″House Under the Kings″, the former seat of the Załuski Library.