Whose theory first explained gravity?

In 1687, Isaac Newton published his law of universal gravitation, proposing that every mass attracts every other mass with a force that depends on their masses and the distance between them. This single idea explained both why objects fall to the ground and why the planets orbit the Sun. Legend says a falling apple sparked his insight. Newton framework governed physics for over two centuries, until Albert Einstein later refined our understanding of gravity as the curving of spacetime.