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In this work, a fundamentally new regime of coherent high-field transport driven by phase stable optical fields has been entered. For the first time, the 80 year old prediction of Bloch oscillations in bulk solids has been confirmed unequivocally. Going beyond the quasi-classical limit of coherent transport on a sub-cycle timescale, the interplay between strongly driven inter- and intraband dynamics leads to a quantum interference phenomenon controlled by the phase of the driving field. These experiments were enabled by an unparalleled technology platform for terahertz (THz) sub-cycle studies, which features a novel technique for ultrashort laser-pulse characterization and sets records in field amplitudes of THz waveforms and high-speed scanning of optical delays. A unique technology platform for contactless biasing with intense THz fields and observation of phenomena on sub-cycle timescales has been established in the first part of this thesis. For ultrashort laser-pulse characterization a novel method based on THz polarization streaking facilitates the routine characterization and compression of ultrabroadband laser pulses. Bandwidths of more than one optical octave are supported and the method is particularly straightforward to use in THz experiments. Opening a new chapter in fast and precise delay scanning systems, the developed acousto-optic fast scan delay reaches sweep rates of 34 kHz and a precision of 15 as, a singular combination of speed and accuracy. A total delay of 6 ps is scanned within 30 us with a resolution limited only by the repetition rate of the laser. The computer-controlled device is fully compatible with commercial laser technology and the combined system is long-term stable with a delay-time jitter as good as 0.8 fs over a period of 5 hours. With atomically strong THz fields and gating pulses with bandwidths as wide as 234 THz, the newly set-up high-field laboratory provides an ideal environment for exploring a novel regime of coherent transport with contactless THz biasing. Already at carrier frequencies of 30 THz, peak amplitudes reach 72 MV/cm, doubling the previous record for intense phase-stable waveforms at these frequencies. Full control of the carrier-envelope phase, center frequencies widely tunable throughout the mid-infrared, and additional beam lines for low-frequency THz generation make the system particularly versatile and set the stage for a rich variety of experiments. In the second part of this work the newly developed sub-cycle technology is applied to enter a new regime of coherent charge transport in atomically strong fields. THz fields drive electron wave packets through the full Brillouin zone of bulk GaSe to perform a complete Bloch cycle within a few femtoseconds, a fraction of the oscillation period of the driving waveform. Such dynamical Bloch oscillations lead to the emission of high-order harmonic radiation in an all-coherent and phase-stable spectrum. Encompassing 12.7 optical octaves from the far-infrared, through the mid-infrared, near-infrared and visible regimes, even bordering on the ultraviolet, this spectral comb sets a new record in all-coherent ultrabroadband radiation from table-top sources. A full quantum-mechanical model of inter- and intraband dynamics, developed at Marburg University, confirms THz-driven Bloch oscillations as the origin of high-harmonics. The phase of the THz waveform sensitively controls the process and quantum interference between inter- and intraband dynamics strongly modifies the emitted radiation.