Complex sentence: For his secondary schooling, he attended the Leys School in Cambridge, England, and later at military colleges in the United Kingdom (including Sandhurst) and United States (including Fort Leavenworth).
Split into simpler sentences: For his secondary schooling, he attended the The Leys School, Cambridge, England. He later attended military colleges in the United Kingdom (including Sandhurst) and the United States (including Fort Leavenworth).