Why is Macbeth's allusion to Tarquin in line 56 of Macbeth, by Shakespeare, particularly appropriate? nope
There were several Tarquins. The reference to his "ravishing strides" suggests an allusion to Tarquin the Proud (Lucius Tarquinius Superbus). He was a tyranical ruler who was eventually overthrown (some say as a fallout from the rape of Lucretia, others for his arrogant and evil rule). Lucretia, like Duncan, was known for her virtue. Tarquin was attracted to her but because she was virtuous, the only way he could have her was through a violent rape that eventually cost her her life (she committed suicide). The story parallels in some way Macbeth's attack on virtue (Duncan) and establishes for the audience a suggestion that if Macbeth were to claim the throne he would reign as Tarquin did--with arrogance and tyrrany.
In this monologue, Macbeth is preparing to murder the king. Essentially, he is so worried about the act he is about to commit that his mind is playing tricks on him. First, he is unable to grasp the dagger, then he thinks he sees blood on the dagger; however, he comes to the conclusion that these manifestations are a result of his nervousness.
Prince Tarquin is known for raping the Roman matron, Lucrece; therefore, this allusion is very appropriate as it seems Macbeth is attempting to evoke the prince's tyrannical spirit in order to proceed with the murder.
Let's not forget that Tulia, Tarquin's wife, manipulated her husband so that he would kill the king to gain power and wealth- Which is exactly Lady Macbeth's role in the play.