On Wednesday, 10 October 2018, more than 200 guests from around the world gathered on the northern array site of the CTA to celebrate the inauguration of the first prototype Large-Sized Telescope (LST). The telescope, named LST-1, is intended to become the first of four LSTs on the north site of the CTA Observatory, which is located on the existing site of the Instituto de Astrofisica de Canarias’ (IAC’s) Observatorio del Roque de los Muchachos located in the municipality of Villa de Garafia on the island of La Palma. The plan for the site also includes 15 Medium-Sized Telescopes (MSTs). The LSTs will expand the science reach to cosmological distances and fainter sources with soft energy spectra. Both the repositioning speed and the low energy threshold provided by the LSTs are critical for CTA studies of transient gamma-ray sources in our own Galaxy and for the study of active galactic nuclei and gamma-ray bursts at high redshift.