Horton first took up league with the Royals in 2011 but it was in his last three seasons as a coach that the club enjoyed their most successful period.
During his tenure the Leamington side have yet to finish outside the top four following promotion to the Midlands Premier Division in 2013 and have only suffered one defeat at their Acre Close home.
Royals chairman Ash Howlett was keen to congratulate Horton.
“We wish Lloyd every success as he starts his new adventure,” said Howlett.
“Lloyd is still an active part of the club and is now an ambassador for the Royals. I have made it clear to the Bears management that Lloyd is only on loan. He learned the game here with the Royals and we want him back one day.”
Following Horton’s departure, recently retired vice-captain Mark Finch will be taking over the coaching reins at the Royals.
As a player Finch tasted victory in the historic Challenge Cup competition where he represented the British Police and Royals are hoping this kind of experience will help prepare them as they aim for a fourth consecutive play-off berth.
Royals train on Wednesday nights (7pm) at Whitnash Sports and Social Club and new players are always welcome.