Complex sentence: When racing was curtailed in England during the first war they sent out Magpie, King Offa, Lanius, Lucknow, Elsdon, Shadowland, Coq d'Or and Escombe to Bradfield, who won races with most of them.
Split into simpler sentences: When racing was curtailed in England during the first war they sent out Magpie, King Offa, Lanius, Lucknow, Elsdon, Shadowland, Coq d'Or. Escombe, and a few other horses to Bradfleld, who won races with most of them.