During a speech at the Royal Institute of British Architects in 1984, Prince Charles expressed his vehement opposition to a proposed extension of the National Gallery in London. He characterized the design proposed by architect Ahrends Burton and Koralek as a 'monstrous carbuncle on the face of a much-loved and elegant friend.' His comments reflected a broader concern regarding the integration of contemporary architecture within the historic fabric of London, a city known for its treasured heritage and architectural elegance. By referring to the design as a 'monstrous carbuncle,' Charles aimed to emphasize the perceived discord between the old and the new, showcasing his support for preserving historical aesthetics in urban settings.

The public reaction to Prince Charles' condemnation was immediate and polarized. Many people echoed his sentiments, arguing for the importance of maintaining London’s visual character, while others criticized him for overstepping his bounds as a royal figure. Architects and urban planners expressed concern that the Prince’s remarks might influence future building legislation and design approvals, fearing that such criticism could stifle innovation and modernization in architecture. The controversy also raised questions about the responsibilities and influence of the Royal Family in cultural and civic matters in Britain.

This episode in architectural discourse highlighted the ongoing tension between modernist design philosophies and traditional aesthetics. Despite the design eventually being approved, the phrase 'monstrous carbuncle' resonated beyond this instance, becoming synonymous with public critique of new architectural proposals that are seen to clash with established historical contexts. The discourse surrounding the National Gallery addition was reflective not only of architecture but also of broader societal attitudes toward change and preservation, which continue to evolve with urban development.