The painting is loosely dated at around 1605, although the artist may have worked on it one year either side of that. There is plenty of documentation around this artwork dating back centuries which makes us confident that it was indeed from his hand. It fits the description of a Caravaggio found within the collection of the Giustiniani family, for example. We also can identify one of the models again in several other Caravaggio paintings, and we know that he would re-use his favoured models from time to time. The recent for the sharp focus on this piece has been due to a number of other controversial claims within this artist's career, where some of those works from his followers have been linked to his own oeuvre. There still remains plenty of question marks around other pieces, but with this one now destroyed, we have little chance of ever being 100% sure of its attribution. Most academics seem content, though, to include it directly into his oeuvre, without any footnotes.
The content refers to Gospel of Matthew (Matthew 26), where Jesus and his disciples climbed the Mount of Olives, which is a famous religious location just outside Jerusalem. The story continues on with Christ finding his colleagues asleep after praying by himself for a period of time. Christ would be arrrested shortly afterwards by soldiers under the direction of Judas, and perhaps their arrival is signalled by Christ's pointed finger within this painting. Caravaggio completed this artwork for Cardinal Benedetto, along with a number of other religion themed artworks such as The Crowning with Thorns (Vienna), The Incredulity of Saint Thomas and also some other pieces that have since been lost. We do know that the artist was also producing work for the patron's brother at the very same time, and so it is possible that he might have called upon the help of his assistants in order to complete these requests in good time.
Christ himself leans over the disciples just as they wake. His halo floats above his head, in order to help us identify him. His colleagues are tired, catching up on some sleep after climbing the Mount of Olives. Caravaggio chooses here to direct light in from our right hand side, deflecting onto the oldest of the disciples as well as the left arm and shoulder of Christ. The other two are kept relatively darkened, as was the style used by Caravaggio throughout his career. He would use this opportunity to demonstrate his exceptional handling of drapery, shere folds of cloth are beautifully recreated in an accurate way that brought everything to life.