Private Eye Philip Marlowe (Bogart) is hired by wealthy socialite Vivian Sternwood to look into the trouble cased by her younger sister Carmen. He follows a trail of murder, pornography, nightclub rogues and the spoiled rich.

Since its release in 1946 The Big Sleep has become a cinematic classic cementing Bacall and Bogart as an on-screen acting force.

In 1997, the U.S. Library of Congress deemed this film "culturally, historically, or aesthetically significant" and preserved to the National Film Registry.

1947’s Dark Passage was next for the pair, a bug screen adaptation of David Goodis’ novel of the same name.

Bogart and Bacall headline a wild tale of an escapee from San Quentin who has his face surgically altered to allow him the freedom to find his wife's murderer.

Now a man without a past, he meets a sultry stranger willing to put him up until his face heals and they can solve the mystery.

The real-life couple’s third big screen partnership was, unlike The Big Sleep and To Have and To Have Not before it, was met with mixed reviews with some criticising Bogart’s performance but praising the work of Bacall.

However over the years the film, which is a lesser known project by the pair, has come to be viewed as another vintage performance by the actors.

Their final on-screen performance together came in Key Largo in 1948 which also starred Edward G. Robinson and Claire Trevor.

A hurricane swells outside, but it's nothing compared to the storm within the hotel at Key Largo. There, sadistic mobster Johnny Rocco (Edward G. Robinson) holes up and holds at gunpoint hotel owner Nora Temple (Lauren Bacall) and ex-GI Frank McCloud (Humphrey Bogart).

McCloud's the one man capable of standing up against the belligerent Rocco. But the post-war world's realities may have taken all the fight out of him.

Key Largo marked the end of the on-screen partnership of Bacall and Bogart however these two movie legends between them and apart played a part in some of cinema’s most memorable moments.

FemlaeFirst Helen Earnshaw