According to Official Guinness Records,
The largest horse parade involved 11,125 horses and their riders and was achieved by the Federation of Mongolian Horse Racing Sport and Trainers (FMHRST) during an event organised by Mr.M.Enkhbold (FMHRST Chairman) and Mr.P.Sergelen (FMHRST Secretary General), in Khui Doloon Khudag, Ulaanbaatar, Mongolia, on 9 August 2013.
The parade covered 4 km (2.49 miles). The participants came from each of the 21 provinces of Mongolia. The youngest horseman was Uurtsaih Gerelt-Od, a boy aged 2 years 8 months. The oldest horseman was Mr.Dashchoimbal Gungaadash aged 90 years.
For a complete list of 2013 records, please visit 2013 Guinness Records in Mongolia.