"What light from yonder window breaks" is a quote from William Shakespeares play Romeo and Juliet. It is spoken by Romeo as he sees Juliet on her balcony. The quote is part of a soliloquy in which Romeo expresses his passion and obsession for Juliet. He compares Juliet to the sun and the moon, and hopes that the light he sees is coming from her window. The quote is often used to demonstrate Romeos love for Juliet and his romantic nature.