Complex sentence: In all the British government had wasted almost £8 million on the expedition, 4,067 men had died (only 106 in combat) and almost 12,000 were still ill in February 1810 and many others were permanently weakened.
Split into simpler sentences: In all the British government had wasted almost £8 million on the expedition, 4,067 men had died (only 106 in combat). Almost 12,000 were still ill in February 1810 and many others remained permanently weakened.