Ramathibodi I

Timeline

1. c. 1341–1346Chao Phraya River basin (Lopburi–Suphanburi area) · CentralThrough marriage alliances and political coalitions, U Thong integrated the city-state powers of Lopburi and Suphanburi, gradually establishing dominance in the middle Chao Phraya and preparing for the later move to found Ayutthaya as his capital.
2. c. 1347–1350U Thong (Suphanburi) · Suphanburi ProvinceAround 1347 U Thong formally acceded at Suphanburi (U Thong), ruling the core of the Chao Phraya basin while maintaining diplomatic relations with Sukhothai to the north and applying military pressure against the Khmer to the south.