Complex sentence: The Bank of Upper Canada was established in 1821 under a Charter granted by the Province of Upper Canada in 1819 and later led by William Allan, a member of the elite Toronto society called the Family Compact.
Split into simpler sentences: The Bank of Upper Canada was a Canadian bank established in 1821 under a Charter granted by the colony of Upper Canada in 1819. At one point it was headed by William Allan, a member of the elite Toronto society called the Family Compact.