History is a story, his story/her story. That is an important point. History is always written by someone: a person. Every historian has his or her own cultural background, which gives an indication of what could be important to that historian. A good historian makes the effort to put that background into perspective, to make it clear to the reader. A good historian explains his viewpoint, his approach. But that is very difficult. Much of your own cultural background you somehow take for granted. Things that are taken for grant risk becoming invisible.
Every history is made; it is designed for a particular purpose and then constructed and crafted, just like a building really. But that is not where the story ends. When a history has been written down, people read it. Those people have their own perspective, their own background. Strangely enough the reader moulds the material nearly as much as the writer. Readers interpret what they read in their own way, against their own background. At no point does history settle down. It is always in a state of flux.
During courses specifically devoted to Theory and History you will probably be asked to study many buildings, ideas and people. Each of these will be geared to help the analysis of an issue that, in some way, is relevant to design.
 Cf. Roland Barthes’ distinction between readerly writing (the way the reader re-writes a text against his own experience) and writerly writing (the intentions of the writer over which, once written, he has little control).