Military history
Popular versus academic military history: In terms of the history profession in major countries, military history is an orphan, despite its enormous popularity with the general public. William H. McNeill points out:

This branch of our discipline flourishes in an intellectual ghetto. The 144 books in question [published in 1968-78] fall into two distinct classes: works aimed at a popular readership, written by journalists and men of letters outside academic circles, and professional work nearly always produced within the military establishment.... The study of military history in universities remains seriously underdeveloped. Indeed, lack of interest in and disdain for military history probably constitute one of the strangest prejudices of the profession.
In recent decades University level courses in military history remain popular; often they use films to humanize the combat experience. For example, Eugene P. A. Scleh, history professor at the University of Maine, has explored the advantages and problems of teaching a course of "Modern War and Its Images" entirely through films. Students said they found the documentaries more valuable than the dramas. However, military historians are frustrated by their marginal status in major history departments.
Academic historians concerned with military topics have their own scholarly organization, Society for Military History. Since 1937 it has published The Journal of Military History. Its four issues a year include scholarly articles reviews of new books, and a bibliography of new publications and dissertations. The Society has 2300 members, holds an annual convention, and gives out prizes for the best scholarship.

Historiography of military history: Historiography is the study of the history and method of the discipline of history or the study of a specialised topic. In this case, military history with an eye to gaining an accurate assessment of conflicts using all available sources. For this reason military history is periodised, creating overlaying boundaries of study and analysis in which descriptions of battles by leaders may be unreliable due to the inclination to minimize mention of failure and exaggerate success. Military historians use Historiographical analysis in an effort to allow an unbiased, contemporary view of records.
One military historian, Jeremy Black, outlined problems 21st-century military historians face as an inheritance of their predecessors: Eurocentricity, a technological bias, a focus on leading military powers and dominant military systems, the separation of land from sea and recently air conflicts, the focus on state-to-state conflict, a lack of focus on political "tasking" in how forces are used.
If these challenges were not sufficient for military historians, the limits of method are complicated by the lack of records, either destroyed or never recorded due to their value as a military secret. Scholars still do not know the exact nature of Greek fire, for instance. Researching Operation Enduring Freedom and Operation Iraqi Freedom, for example, have presented unique challenges to historians due to records that were destroyed to protect classified military information, among other reasons. Historians use their knowledge of government regulation and military organization, and employing a targeted and systematic research strategy to piece together war histories. Despite these limits, wars are some of the most studied and detailed periods of human history.
Military historians have often compared organization, tactical and strategic ideas, leadership, and national support of the militaries of different nations.
In the early 1980s, historian Jeffrey Kimball studied the influence of a historian's political position on current events on interpretive disagreement regarding the causes of 20th century wars. He surveyed the ideological preferences of 109 active diplomatic historians in the United States as well as 54 active military historians. He finds that their current political views are moderately correlated with their historiographical interpretations. A clear position on the left-right continuum regarding capitalism was apparent in most cases. All groups agreed with the proposition, "historically, Americans have tended to view questions of their national security in terms of such extremes as good vs. evil." Though the Socialists were split, the other groups agreed that "miscalculation and/or misunderstanding of the situation" had caused U.S. interventionism." Kimball reports that:

Of historians in the field of diplomatic history, 7% are Socialist, 19% are Other, 53% are Liberal, 11% are None and 10% Conservative. Of military historians, 0% are Socialist, 8% are Other, 35% are Liberal, 18% are None and 40% are Conservative.

Online resources: People interested in military history from all periods of time, and all subtopics, are increasingly turning to the Internet for many more resources than are typically available in nearby libraries. Since 1993, one of the most popular sites, with over 4000 members (subscriptions are free) has been H-WAR, sponsored by the H-Net network based at Michigan State University. H-War has six coeditors, and an academic advisory board that sets policy. It sponsors daily moderated discussions of current topics, announcements of new publications and conferences, and reports on developments at conferences. The H-Net family of lists has sponsored and published over 46,000 scholarly book reviews, thousands of which deal with books in military history broadly conceived. Wikipedia itself has a very wide coverage of military history, with over 180,000 articles. Its editors sponsor Wikipedia:WikiProject Military history and encourage readers to join.

Military and war museums: Military museums specialize in military histories; they are often organized from a national point of view, where a museum in a particular country will have displays organized around conflicts in which that country has taken part. They typically take a broad view of warfare's role in the nation's history. They typically include displays of weapons and other military equipment, uniforms, wartime propaganda, and exhibits on civilian life during wartime, and decorations, among others. A military museum may be dedicated to a particular or area, such as the Imperial War Museum Duxford for military aircraft, Deutsches Panzermuseum for tanks, the Lange Max Museum for the Western Front (World War I), the International Spy Museum for espionage, The National World War I Museum for World War I, the "D-Day Paratroopers Historical Center" (Normandy) for WWII airborne, or more generalist, such as the Canadian War Museum or the Musée de l'Armée. For the Italian alpine wall one can find the most popular museum of bunkers in the small museum n8bunker at Olang / Kronplatz in the heard of the dolomites of South Tyrol. The U.S. Army and the state National Guards operate 98 military history museums across the United States and three abroad.
Curators debate how or whether the goal of providing diverse representations of war, in terms of positive and negative aspects of warfare. War is seldom presented as a good thing, but soldiers are heavily praised. David Lowenthal has observed that in today's museums, "nothing seems too horrendous to commemorate". Yet as Andrew Whitmarsh notes, "museums frequently portray a sanitised version of warfare." The actual bomber that dropped the atomic bomb on Japan became the focus of an angry national controversy with veterans attacking curators and historians when the Smithsonian Institution planned to put its fuselage on public display in 1995. The uproar led to cancellation of the exhibit.

Early historians: The documentation of military history begins with the confrontation between Sumer (current Iraq) and Elam (current Iran) c. 2700 BC near the modern Basra. Other prominent records in military history are the Trojan War in Homer's Iliad (though its historicity has been challenged), The Histories by Herodotus (484–425 BC) who is often called the "father of history". Next was Thucydides whose impartiality, despite being an Athenian, allowed him to take advantage of his exile to research the war from different perspectives by carefully examining documents and interviewing eyewitnesses. An approach centered on the analysis of a leader was taken by Xenophon (430–355 BC) in Anabasis, recording the expedition of Cyrus the Younger into Anatolia.
The memoirs of the Roman Julius Caesar (100–44 BC) enable a comparative approach for campaigns such as Commentarii de Bello Gallico and Commentarii de Bello Civili.

Technological evolution: The nature of warfare never changes, only its superficial manifestations. Joshua and David, Hector and Achilles would recognize the combat that our soldiers and Marines have waged in the alleys of Somalia and Iraq. The uniforms evolve, bronze gives way to titanium, arrows may be replaced by laser-guided bombs, but the heart of the matter is still killing your enemies until any survivors surrender and do your will.

New weapons development can dramatically alter the face of war, the cost of warfare, the preparations, and the training of soldiers and leaders. A rule of thumb is that if your enemy has a potentially war winning weapon, you have to either match it or neutralize it.

Ancient era: Chariots originated around 2000 BC. The chariot was an effective, fast weapon; while one man controlled the maneuvering of the chariot, a second bowman could shoot arrows at enemy soldiers. These became crucial to the maintenance of several governments, including the New Egyptian Kingdom and the Shang dynasty and the nation states of the early to middle Zhou dynasty.
Some of the military unit types and technologies which were developed in the ancient world are:

Slinger
Hoplite
Auxiliaries
Infantry
Archery
Chariots
Cavalry
For settled agrarian civilizations, the infantry became the core of military action. The infantry started as opposing armed groups of soldiers underneath commanders. The Greeks and early Romans used rigid, heavily armed phalanxes.