Professor Jim Mansell, who spent more than 40 years helping to improve the lives of people with learning disabilities, has died after a long illness.

Mansell first began working with people with learning disabilities in 1970, while a student at Cardiff University. There, he set up a student charity and worked with other students to support people with learning disabilities to move out of a large long-stay hospital where conditions were very poor. From this beginning, Mansell went on to become one of the most respected and influential authorities on people with learning disabilities.  

Among his achievements were, in 1983, founding the Tizard Centre at the University of Kent, which is now one of the world's leading research and study centres on learning disability. He also had a significant influence on government policy on learning disability. He wrote the 1993 report into services for people with a learning disability and challenging behaviour - 'Services for People with Learning Disabilities and Challenging Behaviour or Mental Health Needs' - often referred to as the 'Mansell Report' . It was revised in 2007 to support the 'Valuing People' strategy. Accommodation for people with learning disabilities remained a cause for Mansell. He appeared in last year's Panorama programme that uncovered alleged abuse at the Winterbourne View residential care facility in Bristol, condemning what he saw.

Click here to read his column in the Guardian on the scandal. Following this, he helped to form an advisory group to help the Department of Health plan its response to the abuse. In November 2011, he was presented with the Social Care Institute for Excellence (SCIE) Knowledge Award for Outstanding Contribution to knowledge in social care. Mansell was awarded a CBE for services to people with intellectual disabilities in the 2012 Queen's New Year's Honours List and, despite his poor health, made it to Buckingham Palace to receive his award in January. He was also Professor of disability studies in the school of social work and social policy at La Trobe University, Melbourne.

Allan Bowman, chair of SCIE, said: "Jim did so much for people with learning disabilities. SCIE staff voted for Jim when he won the knowledge award and he was a passionate advocate for supporting people with learning disabilities, their families and carers. Our thoughts go out to Jim's family, colleagues and many friends."