The Marble Twin's Story begins with the construction of the St. Regis Hotel. Furious about the 18 story hotel, the wealthy denizens of the neighborhood began rapidly buying up the surrounding real estate in order to control development. On Fifth Avenue between the Union Club and the Plant mansion, George Vanderbilt commissioned the firm Hunt & Hunt to build two matching townhouses. The houses that would become known as the marble twins were built such that they could be combined to form a larger mansion. Completed in 1905, they were in the style of Louis XV and presented Fifth Avenue with a unified facade. The Vanderbilts then sold them to wealthy friends (along with conditions that hotels or apartment buildings would never be built on the grounds.) The Goelet family moved into 547 and Willaim B. Sloane purchased the other for his daughter. Eventually, as society moved northward, the two twins were converted for commercial purposes. Gimpel & Wildenstein, fine art dealers, leased 547 Fifth Avenue and used it as a gallery to sell their collection of old masters. It would largely remain unchanged until American Express renovated it in 1938 in a commercial alteration that destroyed its graceful stone balcony and refined the first story. Seven years later, its twin 645 Fifth Avenue would be demolished. 647 Fifth Avenue would survive though and when Versace leased it in 1995 it would pay for a restoration of its original balcony and first floor. The corner twin is now the last of the many Vanderbilt built mansions that once lined this part of Fifth Avenue.

653 Fifth Avenue ca. The story of 653 Fifth Avenue begins like the story of many of the mansions on Fifth Avenue: with a family dynasty. Morton Plant was the son of a fabulously wealthy railroad magnate Henry Plant. By all accounts, Henry and Morton's relationship was strained and upon his death, Henry attempted to leave his massive fortune to his grandchild. However, Morton was not one to stand idly by and he challenged the will successfully. The money having been secured, Morton began to live the life of a robber baron. Nor was Morton profligate, a successful businessman himself, he built on the advantages given to him by his father. Befitting his newfound status, Plant purchased the land at 653 Fifth Avenue from William Vanderbilt and commissioned the architect Robert W. Gibson to build him a home. Gibson, who had previously designed cathedrals and churches, built the sumptuous six-story mansion with a pillared entrance on 52nd Street. However, while it completed in 1905, the neighborhood around the home was changing. Real estate developers and tradesmen were moving in, and the heirs and robber barons that occupied the area were losing the struggle to preserve the neighborhood. With the Waldorf, St. Regis, Plaza and other hotels opening, the area was getting busier and busier. However, Morton withstood the changing area and his marriage would bring Maisie Plant into the home in 1914. It was Maisie that would give Morton a reason to leave. One day, Maisie was shopping at Cartier's flagship on Fifth Avenue when she spotted a beautiful set of pearls. The double-string set was valued at a million dollars and presented an interesting and unique opportunity. Pierre Cartier had been looking for a showroom that would properly enhance the brand's prestige and Morton was looking to get out of the neighborhood where he built his mansion. A deal was struck: the mansion was traded for 100$ and a string of pearls. Cartier assumed ownership of the mansion and Plant was free to move uptown. Cartier agreed to leave the exterior almost entirely untouched (and until it's 2000 renovation made very few alterations to the interior as well.) Morton Plant's body might not have agreed to the deal however, he died the next year, leaving Maisie single and wealthy. Cartier has preserved and used the mansion ever since as their primary US showroom.