Like most branches of knowledge gathering, the study of history was launched into the Western tradition by the Ancient Greeks and gained most of its modern form in the 19th and 20th centuries.

The Greek author Herodotus (c. 480-430 BC) is the earliest proper historian of which we know. He is still sometimes referred to as the Father of History. In recording the history of the conflict between the Greeks and the Persians, he created an entirely new genre and a new way to organise knowledge, even if it did initially lean heavily on the format of existing forms of literature, such as epic poetry, tragedy, chronicles, ehtnography and medical writing.

While there is a lot of respect for the work of Herodotus, modern scholars tend to be more in awe of his successor, Thucydides (c. 460-400 BC). Thucydides is held to be the first "scientific" historian; he speaks about his method, filters out the influence of divine will, and appears to take an objective stance on his subject despite having been personally involved in the events he describes. Thucydides and his successor Xenophon were regarded as the great examples of how to write history for centuries afterwards. They determined what history was to be about: analysis of political and military events and the deeds of Great Men, usually with the intention to educate and inspire the reader.

There are a lot of big names in the history writing of the early modern period, some of which may sound familiar - Machiavelli, Gibbon, Carlisle, Grote. But arguably the most influential historians of our era were two 19th-century Germans: Leopold von Ranke and Karl Marx.

The former created a new approach to history that sought to detach it from its didactic and moralistic function, and to try and get at what the past was actually like. There has been a great deal of academic controversy over this, but most modern historians still at some fundamental level follow Ranke's interpretation of how history should be done. Apart from encouraging serious study of the sources and a methodological awareness of the past as a radically different world, Ranke has ultimately inspired the modern focus on social history as the real and essential context and cause of the deeds of Great Men that had previously been the exclusive focus of historians.

The latter, meanwhile, was the most influential of the historical philosophers - historians who saw history as subject to universal laws of human nature that could serve both to explain and to predict human behaviour. This was the radical opposite of Ranke's notion of each historical setting as unique. Marx composed a theory of history based on the exploitation of resources that ultimately created (besides political ideologies) the study of economic history as such.

The modern study of history grew out of ongoing controversies between these extreme interpretations of the past. Nowadays you'll find very few people who believe human history to be dictated by laws; on the other hand, you'll also find few historians who believe in true objectivity, or who would neglect social and economic factors in their historical theories.

Now, all the historians and historiographers of this subreddit are likely to take issue with the sweeping statements I've made here, and I realise that I've simplified and skipped over many things. This is just the short short version. I hope it helps!

As for the Big Picture - yes. Many scholars grapple with vast questions that transcend not just subfields of history, but also disciplines such as history, anthropology, geography and so on. The most pervasive of these is, of course, the question: how and why did the West come to rule the world? Ian Morris (Stanford) has recently been asking this question in an even broader sense: why do some communities and cultures end up being more successful than others? It's fascinating stuff. Unfortunately, scholars who try to broaden their scope tend to open themselves up to criticism from specialists in each of the subfields they touch on, so most scholars tend to define their questions more tightly.

This is a very big question, so my answer will be necessarily broad. What you're asking about is a major element in the academic training of historians, it's called historiography.

Each field of history has experienced various major shifts, and there are also trends in scholarship. For a few years now, a popular angle for writing has been "the Atlantic world." Eventually something like that becomes just a buzz word and historians move on to the next thing, usually because somebody wrote something really innovative, and everybody rushed to copy their method.

In the history of science, (my field), some important names are Thomas Kuhn, Daniel Kevles, and Michel Foucault. There are dozens more that I'd consider essential reading for any serious student of the history of science.

Then there is the history of US diplomacy, (my other field), where the big important names go; Alfred Thayer Mahan, William Appleman Williams, and Emily Rosenberg. There are, again, a lot in between, but they each were quite influential.

If you're talking about history in a broad sense, the most important names are Herodotus, Thucydides, Xenophon, Karl Marx, Antonio Gramsci, Michel Foucault. There are others, but they're debatable. For purposes of studying "how history is done," we really just stick to the last three. The Greeks are incredibly important and each had their own innovations in how to record history, but we don't study them to learn how to write history.

Pinpointing huge paradigm shifts* in historiography is fairly straightforward if you want to keep simple. You say Marx and Gramsci, and then you say Foucault. Foucault is familiar to people in all the humanities and social sciences. The guy was wicked smart.

*thanks, Thomas Kuhn!