There is continual argument over the precise definition of each of these periods, and one historian might group them differently, or choose different names or descriptions. As well, even though in many cases the popular change from one to the next can be swift and sudden, the beginning and end of movements are somewhat subjective, as the movements did not spring fresh into existence out of the blue and did not come to an abrupt end and lose total support, as would be suggested by a date range. Thus use of the term "period" is somewhat deceptive. "Period" also suggests a linearity of development, whereas it has not been uncommon for two or more distinctive cultural approaches to be active at the same time. Historians will be able to find distinctive traces of a cultural movement before its accepted beginning, and there will always be new creations in old forms. So it can be more useful to think in terms of broad "movements" that have rough beginnings and endings. Yet for historical perspective, some rough date ranges will be provided for each to indicate the "height" or accepted timespan of the movement.
[NOTE: I'm including the sub-sections (the isms) *only* for organizational purposes since in most cases Wikipedia does not have articles on the various sections/periods/movements/whatever. Similarly for calling out the different cultural forms - art, architecture, philosophy, etc. I also think it is worthwhile to include short descriptions of each movement for similar reasons. The purpose of this page is to help get these areas of Wikipedia filled in - hopefully by folks more knowledgeable in the particular topics than I!]
Graeco-Roman - The Greek culture marked a departure from the other Mediterranean cultures that preceded and surrounded it. The Romans adopted Greek and other styles, and spread the result throughout Europe and the middle east. Together, Greek and Roman thought in philosophy, religion, science, history, and all forms of thought can be viewed as a central underpinning of Western culture, and is therefore termed the "Classical period" by some. Others might divide it into the Hellenistic period and the Roman period, or might choose other finer divisions.
Romanesque -- 11th & 12th centuries. A style (esp. architectural) similar in form and materials to Roman styles. Romanesque seems to be the first pan-European style since Roman Imperial Architecture and examples are found in every part of the continent.
Nominalism -- Can someone well versed in medieval history help figure out how/where this fits in? Rejects Platonic realism as a requirement for thinking and speaking in general terms.
Humanism - 1500ish
Renaissance - use of light, shadow, and perspective to more accurately represent life. Because of how fundamentally these ideas were felt to alter so much of life, some have referred to it as the "Golden Age". In reality it was less an "Age" and more of a movement in popular philosophy, science, and thought that spread over Europe (and probably other parts of the world), over time, and affected different aspects of culture at different points in time. Very roughly, the following periods can be taken as indicative of place/time foci of the Renaissance: Italian Renaissance[?] 1450-1550. Spanish Renaissance[?] 1550-1587. English Renaissance[?] 1588-1629.
Mannerism - anti-classicist movement that sought to emphasize the feeling of the artist himself.
Baroque - emphasizes power and authority, characterized by intricate detail and without the "disturbing angst" of Mannerism. Essentially is exaggerated Classicism to promote and glorify the Church and State. Occupied with notions of infinity.
Neoclassical - 17th-19th centuries - severe, unemotional movement recalling Roman and Greek ("classical") style, reacting against the overbred Rococo style and the emotional Baroque style. It stimulated revival of classical thinking, and had especially profound effects on science and politics. Also had a direct influence on Academic Art in the 1800s. Beginning in the early 1600s with Cartesian thought (see Rene Descartes), this movement provided philosophical frameworks for the natural sciences, sought to determine the principles of knowledge by rejecting all things previously believed to be known about the world. In Renaissance Classicism attempts are made to recreate the classic artforms - tragedy, comedy, and farce.
Romanticism - 1770-1830 - Began in Germany and spread to England and France as a reaction to Neoclassicism. The notion of "folk genius", or an inborn and intuitive ability to do magnificent things, is a core principle of the Romantic movement. Nostalgia for the primitive past in preference to the scientifically minded present. Romantic heroes, exemplified by Napoleon, are popular. Fascination with the past leads to a resurrection of interest in the Gothic period. It did not really replace the Neoclassical movement so much as provide a counterbalance; many artists sought to join both styles in their works.
Realism - 1830-1905 - Ushered in by the Industrial Revolution and growing Nationalism in the world. Began in France. Attempts to portray the speech and mannerisms of everyday people in everyday life. Tends to focus on middle class social and domestic problems. Plays by Isben are an example. Naturalism is a more extreme version of Realism that followed it briefly. Impressionism, based on 'scientific' knowledge and discoveries concerns observing nature and reality objectively.
Art Nouveau - 1880-1905 decorative, symbolic art
Modernism - 1880-1965 - Also known as the Avant-garde movement. Originating in the 19th century with Symbolism, the Modernist movement composed itself of a wide range of 'isms' that ran in constrast to Realism and that sought out the underlying fundamentals of art and philosophy. The Jazz age and Hollywood emerge and have their hey-days.
Postmodernism - 1965-? - A reaction to Modernism, in a way, Postmodernism largely discards the notion that artists should seek pure fundamentals, often questioning whether such fundamentals even exist - or suggestion that if they do exist, they may be irrelevant. Exemplified by movements such as deconstruction, conceptual art, etc.
Superflat[?] - late1990s-? - Suggested by Japanese artist Takashi Murakami. Followed by many young Japanese artists, such as Yoshitomo Nara. The first art movement originated by a Japanese. Murakami forms a collaborative group called "KaikaiKiKi."
Other isms to try to work into the above, if relevant:
idealism imagism mystic(ism) naturalism Sophist(s) Eclectic and Revival Styles