Short answers, pulled from the story.
Cyrus the Great, known to the Greeks as Cyrus the Elder, was the founder of the Achaemenid Empire. Hailing from Persis, he defeated the Median Empire and built what became the largest empire in the world to that point, stretching from Asia Minor to the Indus River.
The accounts of Cyrus the Great's death conflict. Herodotus says he was killed around 529 BC fighting the Massagetae and their queen Tomyris along the Syr Darya, while Xenophon says he died peacefully at his capital Pasargadae. Cuneiform evidence from Babylon proves he died around December 530 BC.
In the Book of Isaiah, Cyrus the Great is anointed by Yahweh and explicitly designated "messiah", the only non-Jewish figure revered in that capacity. He earned this honor by issuing the Edict of Restoration that freed the Jewish people from the Babylonian captivity and enabled the rebuilding of the Temple in Jerusalem.
The Cyrus Cylinder is a clay cylinder inscribed in Akkadian cuneiform, placed in the foundations of the Esagila temple in Babylon after the Persian conquest in 539 BC. It was discovered in 1879 and is kept today in the British Museum in London, where it has been described both as an early declaration of human rights and as an instrument of ancient Mesopotamian propaganda.
Cyrus the Great defeated the Babylonian army at the Battle of Opis on the Tigris just before October 539 BC, then took Sippar on the 10th and Babylon around the 12th, largely without resistance. Herodotus says the Persians diverted the Euphrates until the water dropped to thigh height, letting them march through the riverbed at night.
The tomb of Cyrus the Great is a limestone structure at his capital city of Pasargadae, built around 540 to 530 BC. It still stands and is recognized with Pasargadae as a UNESCO World Heritage site, drawing reverence from millions of Iranians today.
The meaning of the name Cyrus is disputed. It derives from the Old Persian Kūruš, and ancient scholars such as Ctesias and Plutarch linked it to the Sun, while Karl Hoffmann read it as "humiliator of the enemy in verbal contest". Some scholars argue the name is Elamite in origin, meaning "he who bestows care".