Who is General Sternwood?

It is one of the obvious conventions of the private-detective story that the detective meets a client and is given an assignment. Raymond Chandler created General Sternwood for this purpose. The fact that Sternwood is a very rich man explains why Philip Marlowe is calling on him at his home. Ordinarily a private-eye will be in his office and clients will come to him. An example of this conventional scenario is found in the opening of Dashiell Hammett's novel The Maltese Falcon. Brigid O'Shaughnessy comes to Sam Spade's office. If she phoned and asked him to come to her hotel, he probably would turn her down. He could be missing a more valuable client by leaving his office. He wouldn't even know if he wanted her case or whether she had enough money to pay for his time and expenses. But General Sternwood is an important man. He could become a valuable client who might employ Marlowe many times on different matters and even recommend him to wealthy friends. Besides that, Marlowe was recommended by Bernie Ohls, chief investigator for the District Attorney. Marlowe would naturally want to do a good job because such a connection would be invaluable.
Marlowe has to wait while Norris the butler goes to announce him to the General. There Marlowe sees a portrait of the General as a young officer.
The portrait was a stiffly posed job of an officer in full regimentals of about the time of the Mexican war.The officer had a neat black imperial, black mustachios, hot hard coal-black eyes, and the general look of a man it would pay to get along with.
This description is apparently intended for contrast. When Marlowe meets General Sternwood in the hothouse full of orchids, he sees a very old and sick man in a wheelchair who is obviously dying. The General's appearance establishes the theme of death which hovers over the entire novel and is introduced by the title, The Big Sleep.
One of the things Chandler wanted to establish by this highly original meeting of the private-eye with his client is that the old man could have handled his own problems at one time but is now totally dependent on others. Chandler created a character who was very old and very rich. This explains why Marlowe must come to him for the interview and why he is more than willing to do so. The fact that Sternwood is a multimillionaire explains why he has the kinds of problems that require the services of a private detective. There are at least two grifters trying to take money away from the old man. One is Arthur Gwynn Geiger and the other is Joe Brody. Eddie Mars is taking Sternwood's money indirectly because he is blackmailing his daughter Vivian Regan, and she gets all her money from her father. Lash Canino is undoubtedly getting some of the General's money from Eddie Mars because he is keeping Mars's wife in isolation for a reason which doesn't come out until the end of the novel. Money solves a lot of problems and creates a lot of new ones.
Marlowe becomes involved in a typical Raymond Chandler plot. He thinks he only has to get tough with Arthur Gwynn Geiger in order to make him stop trying to blackmail the General with Carmen Sternwood's IOUs. But Geiger gets shot almost immediately and Marlowe finds himself still involved with the ramifications of the General's problems along with the problems of his two daughters.
In the end many people are dead or, like the General, dying. The dead consist of Rusty Regan, Harry Jones, Joe Brody, Arthur Grynn Geiger, Owen Taylor the family chauffeur, and Lash Canino. Carol Lundgren will be executed in "the nice new gas chamber" at San Quentin for killing Joe Brody, whom he mistakenly believes killed his lover Arthur Gwynn Geiger. Marlowe himself barely manages to survive. He reflects on the nastiness of life and the peacefulness of death in a beautiful passage of prose at the very end of the book.
What did it matter where you lay once you were dead? In a dirty sump or in a marble tower on top of a high hill? You were dead, you were sleeping the big sleep, you were not bothered by things like that. Oil and water were the same as wind and air to you. You just slept the big sleep, not caring about the nastiness of how you died or where you fell. Me, I was part of the nastiness now. Far more a part of it than Rusty Regan was. But the old man didn't have to be. He could lie quiet in his canopied bed, with his bloodless hands folded on the sheet, waiting. His heart was a brief, uncertain murmur. His thoughts were as gray as ashes. And in a little while he too, like Rusty Regan, would be sleeping the big sleep.