Distinguished guests from all over the UK descended on London to honour the 150th anniversary of William Perkin's discovery of the first synthetic dye, mauveine.
The celebrations were jointly organised by the RSC, the Historical Chemistry Group and Chilterns & Middlesex Local Section with much of Perkin's history provided by Dr David Leaback.
Guests included descendents of William Henry Perkin and his sister, Mary. The event recreated the celebrations in 1906 when William Perkin invited 200 guests to travel from Greenford to Sudbury.
Visitors gathered at Greenford Station before being given a guided tour en route to the site of the original Perkin and Sons Dyeworks (now Howdens Joinery) in Oldfield Lane.
RSC president Professor Jim Feast then revealed a new plaque dedicated to Perkin's work, fitted over a previous plaque unveiled in 1957 by Sir Robert Robinson which had become in a poor state of repair.
Guests were then taken to Sudbury Neighbourhood Centre, the site of the former New Hall which Perkin set up through the proceeds of the sale of his Greenford Dyeworks.
Dr Leaback gave two lectures about the Perkin Story, and also wrote a play which was performed by children from nearby Sudbury Primary School and enjoyed by guests and parents alike.
Professor Alan Dronsfield, chair of the Historical Chemistry Group, also gave a demonstration of dyeing using mauveine on pieces of silk and other fabrics.
Following this, further plaques were revealed. Mr George Nicholson, Past Master of the Leathersellers company, unveiled two plaques at the front of the adjacent Sudbury Methodist Church. which had been donated by the company.
To round off the celebrations, Michael Kirkpatrick, great-grandson of Perkin, presented the second RSC Landmark plaque to Sudbury Neighbour Centre manager Kathleen Barrett and the Reverend Stan Barker, minister of Sudbury Methodist Church which will be erected inside the Neighbourhood Centre.
Earlier this month, TV star Carol Vorderman helped launch the Perklin celebrations by wearing an original 1860s Victorian dress dyed with the original mauveine dye.