Complex sentence: Subutai returned to Mongolia from the Song campaign in 1248 and spent the rest of his life at his home in the vicinity of the Tuul River (near modern Ulaanbaatar), dying there at the age of 72.
Split into simpler sentences: Subutai returned to Mongolia from the Song campaign in 1248. Subutai spent the rest of his life at his home in the vicinity of the Tuul River (near modern Ulaanbaatar), dying there at the age of 72.