Question: The Eighteenth Dynasty of Egypt is classified as the first Dynasty of what period in ancient Egyptian history between the 16th century BC and the 11th century BC, covering the Eighteenth, Nineteenth, and Twentieth Dynasties of Egypt?

Context articles: Avaris
KV12
Valley of the Kings
New Kingdom of Egypt
Eighteenth Dynasty of Egypt
First Intermediate Period of Egypt
Helwan (cemetery)
Resheph
Amarna letters
Early Dynastic Period (Egypt)

Avaris ( ; Egyptian: ḥw.t wr.t, Budge notation: "Hut-waret", Greek: Αὔαρις, "Auaris" ) was the capital of Egypt under the Hyksos.
 It was located at modern Tell el-Dab'a in the northeastern region of the Nile Delta, at the juncture of the 8th, 14th, 19th and 20th Nomes.
 As the main course of the Nile migrated eastward, its position at the hub of Egypt's delta emporia made it a major administrative capital of the Hyksos and other traders.
 It was occupied from about 1783 to 1550 BC, or from the Thirteenth Dynasty of Egypt through the second intermediate period until its destruction by Ahmose I, the first Pharaoh of the Eighteenth dynasty.
 The name in the Egyptian language of the 2nd millennium BC was probably pronounced *Ḥaʔat-Wūrat 'Great House' and denotes the capital of an administrative division of the land.
 Today, the name "Hawara" survives, referring to the site at the entrance to Faiyum.
 Alternatively, Clement of Alexandria referred to the name of this city as "Athyria".
Located in the Valley of the Kings, Tomb KV12 is an unusual tomb, used originally in the Eighteenth Dynasty of Ancient Egypt, and then again in the Nineteenth and Twentieth Dynasties.
 It was probably used for multiple burials of royal family members, rather like KV5.
The Valley of the Kings (Arabic: وادي الملوك‎ ‎ "Wādī al Mulūk" ), the "Valley of the Gates of the Kings" (Arabic: وادي ابواب الملوك‎ ‎ "Wādī Abwāb al Mulūk" ), is a valley in Egypt where, for a period of nearly 500 years from the 16th to 11th century BC, rock cut tombs were excavated for the Pharaohs and powerful nobles of the New Kingdom (the Eighteenth to the Twentieth Dynasties of Ancient Egypt).
The New Kingdom of Egypt, also referred to as the Egyptian Empire, is the period in ancient Egyptian history between the 16th century BC and the 11th century BC, covering the Eighteenth, Nineteenth, and Twentieth Dynasties of Egypt.
 Radiocarbon dating places the exact beginning of the New Kingdom between 1570 BC and 1544 BC.
The Eighteenth Dynasty of Egypt (notated Dynasty XVIII, alternatively 18th Dynasty or Dynasty 18) is classified as the first Dynasty of the Ancient Egyptian New Kingdom period, lasting from 1549/1550 BC to 1292 BC.
 It boasts several of Egypt's most famous pharaohs, including Tutankhamun, whose tomb was found by Howard Carter in 1922.
 This dynasty is also known as the Thutmosid Dynasty for the four pharaohs named Thutmosis.
The First Intermediate Period, often described as a "dark period" in ancient Egyptian history, spanned approximately one hundred and twenty-five years, from c. 2181–2055 BC, after the end of the Old Kingdom.
 It comprises the seventh (although it is mostly considered spurious by Egyptologists), eighth, ninth, tenth, and part of the eleventh dynasties.
 Very little monumental evidence survives from this period, especially towards the beginning of the era.
 The First Intermediate Period was a dynamic time in history where rule of Egypt was roughly divided between two competing power bases.
 One of those bases resided at Heracleopolis in Lower Egypt, a city just south of the Faiyum region.
 The other resided at Thebes in Upper Egypt.
 It is believed that during this time, the temples were pillaged and violated, their existing artwork was vandalized, and the statues of kings were broken or destroyed as a result of this alleged political chaos.
 These two kingdoms would eventually come into conflict, with the Theban kings conquering the north, resulting in reunification of Egypt under a single ruler during the second part of the eleventh dynasty.
At Helwan south of modern Cairo was excavated a large Ancient Egyptian cemetery with more than 10.000 burials.
 The cemetery was in use from the Naqada Period around 3200 BC to the Fourth Dynasty and again at the beginning of the Middle Kingdom and then up to the Roman Period and beyond.
 The burial ground was discovered and excavated by Zaki Saad in 1942 to 1954.
 Further excavations started in 1997 by an Australian expedition.
 The excavations of Zaki Saad were never fully published, only several preliminary reports appeared.
 Helwan was most likely the cemetery of Memphis in the first Dynasties.
 The tombs range from small pits to bigger elaborated mastabas. Regarding the underground parts of these tombs, two types are attested.
 There are on one side pits with the burial at the bottom and there are on the other side underground chambers, reached via a pit or via a staircase.
 The majority of burials are for one deceased.
 There are some examples of multiple burials.
 The deceased were mostly place in reed mats or coffins of different materials.
 Most of the bodies were found in a contracted position.
 Most tombs were built of mud bricks.
 Roofs are often made of timber.
 Some walls in the underground chambers were covered with plaster.
 In several tombs stones were found, used for roofing the tomb chamber, for blocking the entrance and in rare cases for paving walls.
 Some of the more elaborate tombs had several underground chambers.
 These chambers were often reached via a staircase.
 The people buried here belonged to all levels of society, albeit the highest officials were buried at Saqqara.
 Over 40 stelae were found belonging to the upper levels of society.
 They are an important source for early writing in Egypt.
 A certain Meriiti bears many titles on his stela and dates moast likely to the First Dynasty.
 A few stelae also belong to members of the royal family, such as the "king's daughter" Satkhnum, the "king's daughter" Khenmetptah and the "king's son" Nisuheqet.
 The stela date from about the middle of the First Dynasty to the early Fourth Dynasty.
Resheph (also "Rešef, Reshef"; Canaanite "ršp" רשף ; Eblaite "Rašap", Egyptian "ršpw ") was a deity associated with plague (or a personification of plague) in ancient Canaanite religion.
 The originally Eblaite and Canaanite deity was adopted into ancient Egyptian religion in the late Bronze Age during the Eighteenth Dynasty of Egypt (late 15th century BC) as a god of horses and chariots.
The Amarna letters (sometimes referred to as the Amarna correspondence or Amarna tablets, and cited with the abbreviation EA) are an archive, written on clay tablets, primarily consisting of diplomatic correspondence between the Egyptian administration and its representatives in Canaan and Amurru during the New Kingdom.
 The letters were found in Upper Egypt at Amarna, the modern name for the ancient Egyptian capital of "Akhetaten" (el-Amarna), founded by pharaoh Akhenaten (1350s – 1330s BC) during the Eighteenth dynasty of Egypt.
 The Amarna letters are unusual in Egyptological research, because they are mostly written in Akkadian cuneiform, the writing system of ancient Mesopotamia, rather than that of ancient Egypt.
 The known tablets total 382: 24 tablets had been recovered since the Norwegian Assyriologist Jørgen Alexander Knudtzon's landmark edition of the Amarna letters, "Die El-Amarna-Tafel", published in two volumes (1907 and 1915).
 The written correspondence spans a period of at most thirty years.
The Archaic or Early Dynastic Period of Egypt is the era immediately following the unification of Upper and Lower Egypt  "c." 3100 BC.
 It is generally taken to include the First and Second Dynasties, lasting from the end of the Naqada III archaeological period until about 2686 BC, or the beginning of the Old Kingdom.
 With the First Dynasty, the capital moved from Thinis to Memphis with a unified Egypt ruled by an Egyptian god-king.
 Abydos remained the major holy land in the south.
 The hallmarks of ancient Egyptian civilization, such as art, architecture and many aspects of religion, took shape during the Early Dynastic period.