The IceCube Neutrino Observatory, located at the South Pole, is a
Cherenkov detector that continuously monitors a cubic kilometer of instrumented glacial ice for neutrino interactions in the sub-TeV to EeV energy range. Its
primary design goal is the study of powerful astrophysical objects
that could act as natural particle accelerators and thus as sources of
(ultra) high energy cosmic rays - in short: to do neutrino astronomy.
The first steps have been realized. IceCube has discovered a diffuse
flux of high energy astrophysical neutrinos consistent with being
extra-galactic in origin. In addition it recently obtained evidence for
neutrino emission from the direction of the blazar TXS 0506+056 and
thereby possibly identified a first source of high energy cosmic rays.
Besides high energy astrophysics, IceCube also contributes to
fundamental particle physics through the study of neutrino interactions
at these large energies. In this talk I will present recent IceCube
results of measurements with high energy neutrinos.