What subjects did Edward Gibbon study before he was 15 years old?

Before the age of 15, Edward Gibbon’s education was characterized by irregularity and a spirit of self-sufficiency. While he attended schools such as the grammar school in Kingston and Westminster School, his most significant intellectual development occurred through his own independent reading.1

His primary subjects and areas of focus included:

• History: Gibbon identified this as his "proper food" by his 12th year.1
• Latin: He famously noted in his Memoirs that he acquired a knowledge of Latin syntax at the expense of "many tears and some blood".1
• Chronology: By his 14th year, he was already applying his mind to difficult problems of chronology and had covered the main fields that would later inform his historical work.1

Throughout these early years, Gibbon followed his own intellectual bent, often utilizing the libraries of country houses he visited with his father to pursue his studies in solitary independence.1