Gottfried Semper (1803-1879) was a German architect and theorist known for his influential ideas on architecture and design. He is best recognized for his work on the Semper Opera House in Dresden and for developing the concept of the "four elements of architecture," which include the hearth, the roof, the enclosure, and the mound. His theories emphasized the importance of materials and craftsmanship in architectural design. Semper's writings, particularly his book "The Four Elements of Architecture," have had a lasting impact on architectural theory. He was also a key figure in the Vernacular Architecture movement, advocating for designs that reflect local traditions and materials. His ideas continue to influence architects and designers today.