Newsnight presenter Emily Maitlis, Work and Pensions Secretary Iain Duncan Smith and Chief Rabbi Lord Sacks were among the speakers at Monday's Langdon dinner at the Savoy.
But the real stars of the show were the Langdon residents who addressed the 350 diners, demonstrating how the charity enables young adults with mild-to-moderate learning difficulties to lead independent and productive lives.
Operating in Manchester, Edgware and, imminently, Borehamwood, Langdon offers housing, educational, employment and social opportunities to 150 people. Numbers are growing as it extends both its outreach work and the age range of those assisted.
Having told guests that "your contributions will make a big difference to our lives", Langdon resident Ben Braham added impishly: "We are a terrific group of people."
Following him on the platform, Lord Sacks acknowledged: "Ben, you do this so much better than I do."
Another Langdon resident, Debra Rose, said: "We only want to do the same as anyone else. It is not too much to ask."
Fellow residents Clare Flatter, Kate Landau, Marcus Bean, Scott Bryant, Mark Tish, Gabby Joseph, Abbe Rose Kubel, James Manton and Robyn Freeman also spoke at the dinner, which raised £400,000. Another speaker was Lisa Pathman, whose 15-year-old daughter will be a future Langdon resident. The knowledge that she would enter a safe, secure and supported environment was "priceless", Mrs Pathman said.
Mr Duncan Smith is well aware of Langdon's work, the charity having won an award from the Centre for Social Justice, the independent think-tank he founded that promotes the role of the voluntary sector.
He said that its activities exemplified the Big Society concept, treating people with difficulties "like normal human beings". Others could learn from its success in giving clients "a real and proper life. The principle is that families need to have work. It's not just about money but what shapes us."
Ms Maitlis was clearly moved by her experience of conversing with residents - "meeting the people it's all about makes such a difference", she said.
She hoped guests were gaining an appreciation of "the sheer scale of what Langdon needs to keep its residents active and independent".
In her closing remarks, Ms Maitlis asked: "What can be more important than a place where you can make friends and focus on what your life can be?"
The Chief Rabbi said he felt privileged to have witnessed the growth of Langdon. It combined a professional operation with "a moral beauty which is difficult to describe. What moves me most is the chesed [kindness] of our community."
Proceeds from the dinner will go towards the Borehamwood housing project and the employment programme in London and Manchester.
Langdon's employment schemes require an annual £250,000 outlay. Similar amounts go on educational support and social and recreational activities with a further £1.25 million earmarked for new housing and property maintenance.