Complex sentence: The first British Legation was opened in Tōzen-ji Takanawa, Edo (now Tokyo), 1859, and Sir Rutherford Alcock, then Consul-General, was promoted to the Minister.
Split into simpler sentences: The first British Legation was opened in Tōzen-ji, Takanawa, Edo (now Tokyo), 1859. Meanwhile, Sir Rutherford Alcock, then Consul-General, was promoted to the Minister.