His first intention, in which Bandinelli followed him, was to execute a Hercules trampling upon Cacus, which should stand as pendant to his own David.
By a deliberation of the Signory, under date August 22, 1528, we are informed that the marble had been brought to Florence about three years earlier, and that Michelangelo now received instructions, couched in the highest terms of compliment, to proceed with a group of two figures until its accomplishment.

If Vasari can be trusted, Michelangelo made numerous designs and models for the Cacus, but afterwards changed his mind, and thought that he would extract from the block a Samson triumphing over two prostrate Philistines.

The evidence for this change of plan is not absolutely conclusive.

The deliberation of August 22, 1528, indeed left it open to his discretion whether he should execute a Hercules and Cacus, or any other group of two figures; and the English nation at South Kensington possesses one of his noble little wax models for a Hercules.

We may perhaps, therefore, assume that while Bandinelli adhered to the Hercules and Cacus, Michelangelo finally decided on a Samson.