Frank Lloyd Wright passed away on April 9, 1959, at the age 91, six months before the Guggenheim opened its doors. Wright is widely considered the greatest architect of the 20th century, and the greatest American architect of all time. He perfected a distinctly American style of architecture that emphasized simplicity and natural beauty in contrast to the elaborate and ornate architecture that had prevailed in Europe. With seemingly superhuman energy and persistence, Wright designed more than 1,100 buildings during his lifetime, nearly one third of which he designed during his last decade. The historian Robert Twombly wrote of Wright, "His surge of creativity after two decades of frustration was one of the most dramatic resuscitations in American art history, made more impressive by the fact that Wright was seventy years old in 1937." Wright lives on through the beautiful buildings he designed, as well as through the powerful and enduring idea that guided all of his work—that buildings should serve to honor and enhance the natural beauty surrounding them. "I would like to have a free architecture," Wright wrote. "Architecture that belonged where you see it standing—and is a grace to the landscape instead of a disgrace."