The 1965 show trial of writers Yuli Daniel and Andrei Sinyavsky, charged with anti-Soviet agitation and propaganda, and the subsequent increased repression, marked the demise of the Thaw and the beginning of harsher times for samizdat authors. The trial was carefully documented in a samizdat collection called "The White Book" (1966), compiled by Yuri Galanskov and Alexander Ginzburg. Both writers were among those later arrested and sentenced to prison in what was known as Trial of the Four. In the following years some samizdat content became more politicized, and played an important role in the dissident movement in the Soviet Union.