Archaeologists have discovered that Tilos was first inhabited in the Neolithic times and during antiquity, the island was well-known for its perfumes and salves. Excavations in Charkadio Cave, in the center of the island, have revealed the bones of a strange kind of animals, the dwarf elephants, that dominated the island about 6 million years ago. These findings are exhibited today in the Paleontological collection in Megalo Chorio.
According to Greek mythology, the island took its name from a man named Tilos, son of god Helios. It is believed that Tilos used to gather therapeutic plants for his ill wife on this island and later on they built a temple to which he became the priest. The first inhabitants were Pelasgians and Minoans. In the 7th century BC, the residents of Tilos and Lindos, on Rhodes, founded a colony in Sicily, Italy, and in the 5th century, Tilos became part of the Athenian League, as most islands of the Aegean.
In the 4th century BC, the island was independent and issued its own coins. In the centuries to follow, Tilos was a dependant of neighboring Rhodes, which had a powerful naval power. In the second century BC, it was dominated by the Romans and then it was included in the Byzantine Empire. In 1309 AD, the history of Tilos is marked by the Venetian occupation. The Knights of Saint John conquered the island and built a Castle in Megalo Chorio to protect it from pirates.
Because of its strategic position (on the crossroad between the East and the West), Rhodes has been under constant attacks and dominations from the early times. The first settlers of the island came from Asia and some evidence of a Mycenaean settlement has been found. The Dorians were the next settlers. In 500 BC Rhodes was already a strong power. There were also many temples and structures such as the Acropolis of Rhodes built in this time period.
After the naval Battle of Salamis and the defeat of the Persians, the island became a part of the Delian League, an organization of which Athens was the leader. During this period, in 480 BC, the three earliest city-states of Rhodes, Ialyssos, Lindos, and Kameiros, combined and formed the modern town of Rhodes. With the reign of Alexander the Great, Rhodes fell under Macedonian domination. After the fall and fragmentation of the Empire of Macedonia, the island of Rhodes fought for its freedom and, after a long siege, triumphed in 305 BC.
It was during this period that the Colossus of Rhodes, one of the Seven Wonders of the World, was constructed and straddled the harbor. This impressive giant statue was demolished during an earthquake. In a period of 150 years, the island flourished and showed its great navigation and maritime skills, establishing its reputation as one of the best in these domains. In 70 AD, Rhodes fell under the Roman rule which lasted for 300 years. Then, it became part of the Byzantine Empire.
Because of its strategic position, Rhodes was conquered successively by Turks, Persians, and Saracens. The history of Rhodes was primarily marked by the occupation from the Venetians in the Medieval times. The Knights of Saint John fortified the City of Rhodes with citadels, castles and built the Palace of the Grand Master. Many Castles were also built in the countryside, such as the Castle of Monolithos and also the Medieval Castle of Kritinia.
In 1523, after a long siege, the Ottomans took control of the island, who remained until 1912. During the First World War, Rhodes was taken by the Italians till 1943. The Italians contributed to the development of the island, with the renovation of important sites and the construction of nice buildings, such as the National Theatre. In 1947, Rhodes and all Dodecanese islands became part of the Greek State.
In 1523, Tilos was conquered by the Ottomans and then in the 20th century by the Italians. It was incorporated into Greece in 1948, as the rest of the Dodecanese did. In the 1950s, the inhabitants were facing an economic decline and a large part of them moved to Rhodes, Athens or abroad. The rest were trying to make their living with agriculture and fishing. Now, Tilos is a small and remote island with about 500 inhabitants. Its economy is still based on agriculture, cattle breeding, and fishing, while in summer, it receives few tourists seeking for peaceful vacations.