In summer 1998, Marshall discontinued their entry-level Park line of amps, and moved the models over to the Marshall line. Since these amps utilize solid-state electronics, Marshall was wary of putting his name on any solid-state product. After five years of the Park amps, Marshall decided that they had earned enough credentials and moved them into the Marshall line with the models G10MKII, G15RCD, G30RCD, and the G215RCD. In 1999, the G50RCD, G80RCD, G100RCD, and MG412A and B speaker cabinets were introduced along with a G15MS Micro Stack that featured a G15RCD in head configuration and two small speaker cabinets.
Marshall initially referred to these amplifiers as the Marshall Park Series. In 1999, they began calling them the MG Series, although they never had "MG" in the model name (aside from the speaker cabinets). The MG probably stands for the Marshall G Series, and this line of amps should be referred to as the MG II Series, since they were all replaced in 2002 with the MG III Series.