After 1800, the heirs of Prithvi Narayan Shah proved unable to maintain firm political control over Nepal. A period of internal turmoil followed. The rivalry between Nepal and the British East India Company over the princely states bordering Nepal and British-India eventually led to the Anglo-Nepalese War (1814–16), in which Nepal suffered substantial losses due to lack of guns and ammunitions against the British-Indian forces with advanced weapons. The Treaty of Sugauli was signed in 1816, ceding large parts of the Nepalese controlled territories to the British. In 1860 some parts of western Terai, known as "Naya Muluk" (new country) was restored to Nepal.