when was this?
1919
Equestrian statue of Edward Horner
 In 1919, he was beginning to move into sculpture. The Horner memorial was his first public work of sculpture, for which Lutyens commissioned him based on a pre-existing friendship.
where is the equestrian statue of edward horner located? Inside St Andrew's Church in the village of Mells in Somerset, south-western England. who designed it? Sir Edwin Lutyens
wiki:10083118
Equestrian statue of Edward Horner [SEP] Commissioning
Alfred Munnings was a painter specialising in horses. He volunteered for military service at the outbreak of war but was deemed unfit due to lack of sight in one eye. He volunteered to tend to army horses and was later recruited as a civilian war artist attached to Canadian cavalry. In 1919, he was beginning to move into sculpture. The Horner memorial was his first public work of sculpture, for which Lutyens commissioned him based on a pre-existing friendship. The work led to several further commissions for equine statues, including from the Jockey Club for a sculpture of the racehorse Brown Jack at Epsom Downs Racecourse.