General Relativity incorporated gravity into the mix. It describes gravity not as a force, but as the curvature of spacetime caused by massive objects. According to General Relativity, the curvature of spacetime around an object like the Earth causes objects to fall towards its center, which we experience as gravity. 

In November 1915, Einstein expanded on his Special Theory of Relativity with his General Theory of Relativity, which he published formally in 1916. This theory introduced the concept that gravity is not a force as traditionally conceived but rather a curvature of spacetime itself, caused by mass and energy. General Relativity provides a comprehensive description of gravitational phenomena and has been confirmed by numerous experiments and observations, including the bending of light by gravity and the precise orbit of planets.