Short answers, pulled from the story.
Shakespearean tragedy is the designation given to most tragedies written by William Shakespeare. Scholars define the category by the First Folio's original classification, though some plays remain disputed because their subject matter, setting, or ending does not fit neatly into tragedy, history, comedy, or the later category of the problem play coined by Frederick S. Boas.
Shakespeare drew on Plutarch's The Lives of Noble Grecians and Romans for the Roman plays, and on Holinshed's Chronicles for his Britain-based plays and Hamlet. Othello and Measure for Measure are exceptions, based on narrative fictions by Italian writer Giraldi Cintio. The story of Lear traces back as far as Geoffrey of Monmouth's Historia regium Britanniae around 1135.
Shakespeare's history plays were classified separately in the First Folio because they are based on real figures from the history of England. The Roman plays, also based on historical figures, were classified as tragedies because their sources were foreign and ancient rather than English.
The tragic flaw, or hamartia, is a concept from Senecan tragedy describing a grave error or fatal weakness in a noble character that triggers a reversal of fortune (peripeteia). Some critics have argued that this pseudo-Aristotelian concept does not cleanly apply to Shakespeare's tragic figures, and the question remains debated among scholars.
Titus Andronicus is believed to be Shakespeare's earliest tragedy, estimated to have been written between 1591 and 1593. Romeo and Juliet followed in 1594-1595, with the major sequence of tragedies including Hamlet, Othello, King Lear, and Macbeth coming in the decade that followed.
The French author Belleforest published The Hystorie of Hamblet, Prince of Denmarke in 1582, which Shakespeare drew on for Hamlet. That earlier text included specifics such as the prince feigning madness and the scene in which the prince kills the king's counsellor who was eavesdropping from behind an arras in the queen's chamber.