Born December 2, 1795 in Wingham, Kent, Miller was fluent in several languages by the age of seventeen, when he enrolled in the British army to fight in the Napoleonic Wars,[1] taking part in the Siege of Badajoz and Battle of Vittoria under the Duke of Wellington.

In September 1817, hearing of the wars in Latin America, he set sail for Buenos Aires to join San Martín's Army of the Andes.

[2] He took part in San Martín's liberation of Chile, participating in the decisive battle of Maipú, and then joined Lord Cochrane as the commander of marines in the Chilean Navy.

General Miller – while suffering from malaria – played a big part in the Battle of Torata: storming the hills and taking them when everything seemed to be lost.

During these wars Miller was wounded twenty two times, and after his death the autopsy revealed he had carried two bullets in his liver for 40 years.

On June 11, 1834, in appreciation for services rendered to the existing government, General Miller received promotion to the rank of Grand Marshal, the highest military grade in Peru.