Rolex has launch a great number of models that have become classics. Many of these bear the moniker "Oyster Perpetual." While the name Oyster Perpetual doesn't designate a particular model or line, it does imply a few things. First, that the watch will have the trademark Rolex Oyster case. Second, that the movement beating inside that Oyster case will be Rolex's famed Perpetual movement.

The quest for a waterproof and dust-proof watches began shortly before the First World War. Many notorious watch makers worked on the development including Paul Perregaux y George Peret who found the formula to make a watch waterproof. Rolex rapidly realized that  a hermetically sealed case, together with careful fitting of the crystal and a special stem mechanism, would produce a better wristwatch.  Hans Wilsdorf, Rolex founder, quickly negotiated to have the Perregaux and Peret patent assigned to him and he obtained a British patent on October 18, 1926. It gained notoriety in 1927, when Mercedes Gleitze became the first British woman to swim across the English Channel, wearing a Rolex during her 15 hours and 15 minutes swim.

As with the Oyster case, the Perpetual movement saw many versions before finally being perfected in the 1930s. Rolex's first automatic movement quietly debuted in 1931, without the fanfare that followed the introduction of the Oyster case. The movement was met with some consternation from purists who decried the "extreme novelty" of a self-winding watch. Nevertheless, Rolex could see that they had struck gold with the Perpetual movement. They continued to develop and improve it over the years, establishing a line of watches that would stand as an alternative to Rolex's sportier models. 

The Oyster Perpetuals of the 1960s and 1970s still are some of Rolex's best-loved timepieces. Elegant, with clean lines, the watches are nevertheless sturdy, coming in stainless Steel or 18k yellow or pink gold. Produced from 1963 to 1980, the Rolex Oyster Perpetual Date Reference 1501 resembles the better-known Datejust, particularly the more commonly-recognizable Ref. 1601/1603. The most obvious resemblance is the milled bezel. Artfully designed, the fixed bezel is raised at hour intervals with hash marks in between, drawing the eye outward from the center, producing a wonderful radiant visual effect. For a perceptive collector who would like a vintage Rolex, but doesn't necessarily want to go for a Datejust, the Oyster Perpetual Date Ref. 1501 can be an attractive alternative.