Lufthansa started a Berlin service with Bae146 in May 2001, but as I understand it gave the route up in early 2002 as part of the post-9/11 cutbacks. It was on a BAe146.
The first jet service out of LCY was to Berlin Tempelhof, by small carrier Conti-Flug. This ran from 1991 to 1994, when Conti went out of business, again with the 146.