Speakers paying tribute in Westminster Central Hall on Thursday included former deputy prime minister John Prescott, who described Mr Bickerstaffe as a “giant” of the labour movement in the UK and abroad.
“He stood for social justice and peace – and everyone knew he was on their side,” he said.
Unison general secretary Dave Prentis said Mr Bickerstaffe was widely admired and respected, adding: “If you knew him, you loved him. He always had time to listen to the people he represented. He gave a voice to the voiceless and power to the powerless.”
Actress Maxine Peake said Mr Bickerstaffe’s skills as an orator were unrivalled, while Labour leader Jeremy Corbyn said if the former Unison leader was still alive, he would be campaigning to bring peace to Syria.
Music at the service was provided by the Dodworth Colliery Band and the choir of Unison, the union he led from 1996 to 2001.
Mr Bickerstaffe, who died last October aged 72, was general secretary of the public sector union NUPE before it became Unison and was a former president of the TUC.
He also served as president of the National Pensioners Convention for four years from 2001.
Mr Bickerstaffe, who was educated and lived in Doncaster in his early career, moved to the town as a child and was educated at Doncaster Grammar School and in sociology at Rutherford College of Technology.
He became an organiser for the National Union of Public Employees (NUPE) in 1966 in Yorkshire, rising through the ranks to be divisional officer of the northern division.
He then became national officer responsible for members working in local government, universities and the water industry and in 1981 was appointed NUPE general secretary.
When NUPE, COHSE and NALGO merged to create Unison in July 1993, Bickerstaffe became associate general secretary.
He was elected general secretary in November 1995, taking office in 1996.
He retired from Unison in 2001 and succeeded Jack Jones as president of the National Pensioners Convention in April 2001.
He also had honorary doctorates from Keele University, the University of Hertfordshire and Sheffield Hallam University as well as the Freedom of the Borough of Doncaster.