http://www.theatrehistory.com/british/marlowe003.html

Meanwhile, Mycetes, the not too bright King of Persia, has heard that
Tamburlaine might have designs on the throne of Persia. He therefore sends one
of his lords, Theridamas, with a thousand horsemen to take Tamburlaine
prisoner. Such is the Scythian's eloquence, however, that Theridamas and his
cavalry join Tamburlaine's ranks. Hearing this, Mycetes' brother, Cosroe,
decides that the help of so powerful a man as Tamburlaine might make his own
chances of seizing his brother's crown more sure. Accordingly he promises
Tamburlaine preferment if he will help to unseat Mycetes. Tamburlaine and his
followers do so, then turn on Cosroe and dispatch him, taking Persia for
themselves.

By this time Zenocrate is as much in love with Tamburlaine as he with her. The
Persian crown, alone, he decides, is all too little to offer her great beauty. His
insatiable ambition impels him next to try his fortunes against the all-powerful
Bajazeth, emperor of Turkey. After this conquest Tamburlaine is drunk with
success. It becomes his custom on the first day of a seige to have his camp and
all his accoutrements in purest white as an indication prompt surrender will save
all bloodshed. Failing to receive the city's submission, the second day sees
Tamburlaine's camp decked out in crimson as a sign that the resisting forces will
be put to the sword. The third day all is deepest black spelling death for every
living being in the hapless city.

From Act II Scene 7

COSROE. Barbarous and bloody Tamburlaine,
Thus to deprive me of my crown and life!
Treacherous and false Theridamas,
Even at the morning of my happy state,
Scarce being seated in my royal throne,
To work my downfall and untimely end!
An uncouth pain torments my grieved soul,
And death arrests the organ of my voice,
Who, entering at the breach thy sword hath made,
Sacks every vein and artery of my heart.
Bloody and insatiate Tamburlaine!
TAMBURLAINE. The thirst of reign and sweetness of a crown,
That caused the eldest son of heavenly Ops
To thrust his doting father from his chair,
And place himself in the imperial heaven,
Moved me to manage arms against thy state.
What better precedent than mighty Jove?
Nature, that framed us of four elements
Warring within our breasts for regiment,
Doth teach us all to have aspiring minds.
Our souls, whose faculties can comprehend
The wondrous architecture of the world
And measure every wandering planet's course,
Still climbing after knowledge infinite,
And always moving as the restless spheres,
Will us to wear ourselves and never rest,
Until we reach the ripest fruit of all,
That perfect bliss and sole felicity,
The sweet fruition of an earthly crown.
THERIDAMAS. And that made me to join with Tamburlaine;
For he is gross and like the massy earth
That moves not upwards, nor by princely deeds
Doth mean to soar above the highest sort.