The Palatine Hill, (; Latin: Collis Palatium or Mons Palatinus; Italian: Palatino [palaˈtiːno]) which is the centremost of the Seven Hills of Rome, is one of the most ancient parts of the city and has been called "the first nucleus of the Roman Empire." The site is now mainly a large open-air museum while the Palatine Museum houses many finds from the excavations here and from other ancient Italian sites.
Imperial palaces were built here started by Augustus. Even before Imperial times the hill was mostly occupied by the houses of the rich.
The hill originally had two summits separated by a depression; the highest part was called Palatium and the other Germalus (or Cermalus).
According to Livy (59 BC – AD 17) the Palatine hill got its name from the Arcadian settlement of Pallantium. More likely, it is derived from the noun palātum "palate"; Ennius uses it once for the "heaven", and it may be connected with the Etruscan word for sky, falad.
The name of the hill is the etymological origin of the word palace and its cognates in other languages (Greek: παλάτιον, Italian: palazzo, French: palais, Spanish: palacio, Portuguese: palácio, German: Palast, Czech: palác, etc.).[a]
The Palatine Hill is also the etymological origin (via the Latin adjective palatinus) of "palatine", a 16th century English adjective that originally signified something pertaining to the Caesar's palace, or someone who is invested with the king's authority. Later its use shifted to a reference to the German Palatinate. The office of the German count palatine (Pfalzgraf) had its origins in the comes palatinus, an earlier office in Merovingian and Carolingian times.
Another modern English word "paladin", came into usage to refer to any distinguished knight (especially one of the Twelve Peers of Charlemagne) under Charlemagne in late renditions of the Matter of France.[b]
Another legend occurring on the Palatine is Hercules' defeat of Cacus after the monster had stolen some cattle. Hercules struck Cacus with his characteristic club so hard that it formed a cleft on the southeast corner of the hill, where later a staircase bearing the name of Cacus was constructed.
Rome has its origins on the Palatine. Excavations show that people have lived in the area since the 10th century BC. Excavations performed on the hill in 1907 and again in 1948 unearthed a collection of huts believed to have been used for funerary purposes between the 9th and 7th century BC approximating the time period when the city of Rome was founded. 
According to Livy, after the immigration of the Sabines and the Albans to Rome, the original Romans lived on the Palatine. The Palatne Hill was also the site of the ancient festival of the Lupercalia.
Many affluent Romans of the Republican period (c.509 BC – 44 BC) had their residences there.
From the start of the Empire (27 BC) Augustus built his palace there and the hill gradually became the exclusive domain of emperors; the ruins of the palaces of at least Augustus (27 BC – 14 AD), Tiberius (14 – 37 AD) and Domitian (81 – 96 AD) can still be seen.
From the 16th century, the hill was owned by the Farnese family and was occupied by the Farnese Gardens, still partially preserved above the remains of the Domus Tiberiana.
At the top of the hill, between the Domus Flavia and the Domus Augustana, the Villa Mattei was built in the 16th century, then purchased around 1830 by the Scot Charles Mills who turned it into an elaborate neo-Gothic villa. At the end of the 19th century the villa was converted into a convent. This was partially demolished from 1928 to allow excavations and in the surviving part of the building the Palatine Museum has been installed.
Dominating the site is the Palace of Domitian which was rebuilt largely during the reign of Domitian over earlier buildings of Nero. Later emperors, particularly those of the Severan Dynasty, made significant additions to the buildings, notably the Domus Severiana.
The building is located near the Temple of Magna Mater at the western end of the hill, on a lower terrace from the temple. It is notable for its beautiful frescoes.
Already during Augustus' reign an area of the Palatine Hill was subject to a sort of archaeological expedition which found fragments of Bronze Age pots and tools. He declared this site the "original town of Rome." Modern archaeology has identified evidence of Bronze Age settlement in the area which predates Rome's founding.
Intensive archaeological excavations began in the 18th century and culminated in the late 19th century, after the proclamation of Rome as the capital of the Kingdom of Italy. Discoveries continued spasmodically throughout the 20th century until the present time.
In 2006, archaeologists announced the discovery of the Palatine House, believed to be the birthplace of Rome's first Emperor, Augustus. A section of corridor and other fragments under the Hill were found and described as "a very ancient aristocratic house." The two-story house appears to have been built around an atrium, with frescoed walls and mosaic flooring, and is situated on the slope of the Palatine that overlooks the Colosseum and the Arch of Constantine. The Republican-era houses on the Palatine were overbuilt by later palaces after the Great Fire of Rome (AD 64), but apparently this one was not and perhaps was preserved for an important reason. On the ground floor, three shops opened onto the Via Sacra. The location of the domus is significant because of its potential proximity to the Curiae Veteres, the earliest shrine of the curies of Rome.
In 2007 the legendary Lupercal cave was claimed to have been found beneath the remains of the Domus Livia (House of Livia) on the Palatine. Archaeologists came across the 16-metre-deep cavity while restoring the decaying palace, with a richly decorated vault encrusted with mosaics and seashells. The Lupercal was probably converted to a sanctuary by Romans in later centuries. Many Others have denied its identification with the Lupercal on topographic and stylistic grounds, and believe that the grotto is actually a nymphaeum or underground triclinium from Neronian times.