Complex sentence: He was then called up for National Service as a second lieutenant in the Royal Artillery, serving in Germany before graduating from Clare College, Cambridge with a history degree and studying at the University of Virginia Graduate School in the USA.
Split into simpler sentences: He was then called up for National Service as a second lieutenant in the Royal Artillery, serving in Germany and graduated from Clare College, Cambridge with a history degree. He gained a place at the University of Virginia Graduate School in the USA.