87–1810). From his initial capital Ambohimanga, and later from the Rova of Antananarivo, this Merina king rapidly expanded his rule over neighboring principalities, with the intention of bringing the entire island under his control, an ambition largely achieved by his son and successor, King Radama I (1810–28). Radama concluded a treaty in 1817 with the British governor of Mauritius to abolish the lucrative slave trade in return for British military and financial assistance. Artisan missionary envoys from the London Missionary Society began arriving in 1818 and included such key figures as James Cameron, David Jones and David Griffiths, who established schools, transcribed the Malagasy language using the Roman alphabet, translated the Bible, and introduced a variety of new technologies to the island.
Radama's successor, Queen Ranavalona I (1828–61), responded to increasing political and cultural encroachment on the part of Britain and France by issuing a royal edict prohibiting the practice of Christianity in Madagascar and pressuring most foreigners to leave the territory. Among those who continued to reside in Imerina were Jean Laborde, an entrepreneur who developed munitions and other industries on behalf of the monarchy, and Joseph-François Lambert, with whom then-Prince Radama II signed a controversial trade agreement termed the Lambert Charter. Succeeding his mother, Radama II (1861–63) attempted to relax the queen's stringent policies, but was overthrown two years later by Prime Minister Rainivoninahitriniony (1852–1865) and an alliance of noble courtiers, who sought to end the absolute power of the monarch. Following the coup, the courtiers offered Radama's queen Rasoherina (1863–68) the opportunity to rule, if she would accept a power sharing arrangement with the Prime Minister—a new social contract that would be sealed by a political marriage between them. Queen Rasoherina accepted, first wedding Rainivoninahitriniony, then later
