Final answer:
The Greek god who ruled the universe and symbolized the sky or heaven was Uranus. As the husband of Gaia, he sired the Titans and was integral to the ancient Greeks' explanations of natural phenomena and their cosmological stories. The name Uranus is still linked to the celestial with the planet bearing his name.
Step-by-step explanation:
Greek Mythology and the First Ruler of the Universe
In Greek mythology, the ancient deity that ruled the universe, signifying the sky or heaven, and was married to Gaia, or Earth, is Uranus. He was not just a god but was also the personification of the sky itself, often depicted as a dome studded with stars. The Greeks' cosmology started with the primordial deities, and among them, Uranus and Gaia were the progenitors of the first generation of Titans, who were crucial in the shaping of the world and lore that followed.
Uranus was the literal sky, which the Greeks saw as an enormous brass dome encapsulating the world, glittering with stars. His story, along with those of other deities from Greek mythology such as Zeus and Hera, provided explanations for the world around the ancient Greeks and included a pantheon of gods and goddesses that governed various aspects of the natural and supernatural world.
The link between deities and celestial objects was deeply ingrained in Greek culture, with planets being named after various gods due to their supposed powers and influence. This cultural heritage persists even today as planet Uranus maintains the tradition of names steeped in mythology.