Reference 5396 was introduced to the market in 2006 and in 2008, Patek Philippe launched this model in white gold. It pays tribute to the firm's celebrated Calatrava model, launched in the 1930s. The smooth white gold case is of the distinctive classic round Calatrava style of reference 96 and stands out by its large size. This striking design of the reference 5396 differs from other Patek Philippe annual calendar models as for the first time features twin day and month apertures beneath 12 o'clock, reminiscent of the reference 3448 and 3450. With its modern yet timeless design, the reference 5396 immediately became a classic among collectors.