The 4f n →4f n - 1 5d(fd) excitation spectra of the light lanthanides (Ce 3 Pr 3 + , Nd 3 + , Sm 3 + , and Eu 3 + ) incorporated in LiYF 4 , CaF 2 , and YPO 4 are investigated in the ultraviolet and vacuum-ultraviolet spectral region (100-250 nm). In these host lattices fine structure (zero-phonon lines and vibronic lines) is observed for fd transitions involving the lowest 5d crystal-field state. The observation of zero-phonon lines makes it possible to analyze the complicated structure in the fd spectra and to compare the experimentally observed spectra with energy-level calculations for the 4f n - 1 5d states. Energy-level and intensity calculations were performed by an extension of the commonly used theory for energy-level calculations of 4f n states. A good agreement between experiment and theory is obtained for the overall structure using the crystal-field splitting (from the spectra of Ce 3 + ), the parameters for the splitting of the 4f n - 1 core (from the literature on energy level calculations for 4f n states) and the spin-orbit coupling of the 5d electron and Coulomb interaction between 4f and 5d electrons (from atomic parameters using the computer code of Cowan).