This paper reports the first observation of high harmonic generation (HHG) driven by quantum light, specifically by bright squeezed vacuum (BSV). BSV is a macroscopic quantum state of light generated at the output of a strongly pumped optical parametric amplifier, characterized by a broad photon-number distribution and sub-cycle electric field fluctuations. The authors demonstrate that BSV enhances the yield of high harmonics compared to classical light, revealing a boost in multiphoton processes. This enhancement is attributed to the superbunching properties of BSV, which allows for a broader range of intensity scaling and higher-order harmonics. The study also shows that BSV can suppress sample damage, enabling the exploration of electron dynamics in solids beyond the conventional damage threshold. The findings contribute to the development of quantum optics with extreme intensities and provide a new method for studying extreme nonlinearities in solids.This paper reports the first observation of high harmonic generation (HHG) driven by quantum light, specifically by bright squeezed vacuum (BSV). BSV is a macroscopic quantum state of light generated at the output of a strongly pumped optical parametric amplifier, characterized by a broad photon-number distribution and sub-cycle electric field fluctuations. The authors demonstrate that BSV enhances the yield of high harmonics compared to classical light, revealing a boost in multiphoton processes. This enhancement is attributed to the superbunching properties of BSV, which allows for a broader range of intensity scaling and higher-order harmonics. The study also shows that BSV can suppress sample damage, enabling the exploration of electron dynamics in solids beyond the conventional damage threshold. The findings contribute to the development of quantum optics with extreme intensities and provide a new method for studying extreme nonlinearities in solids.