He's the longest reigning monarch of all time. Well, out of the ones that we know of at least, but it's unlikely that any ancient kings could have survived so long AND be given the crown at such a young age.
Apparently King Sobhuza had about 180 children that lived past infancy, and estimates are that he had over 1,000 grandchildren. That's nearly 0.1% of the population of Swaziland.
I don't know why this website recognises Taiwan as an actually country. It CLEARLY belongs to China, according to 189 countries and the UN. China doesn't think, they know Taiwan is theirs! Suggest correction