He was the tenth but seventh surviving son of Ernest I, Duke of Saxe-Gotha and Elisabeth Sophie of Saxe-Altenburg.
hiː wʌzðə tˈɛnθ bˌʌt sˈɛvənθ sɚvˈaɪvɪŋ sˈʌn ʌv ˈɜːnɪst ˈaɪ, dˈuːk ʌv sˈæksɡˈɑːθə ænd ᵻlˈɪzəbəθ sˈoʊfi ʌv sˈæksˈɔːlʔn̩bˌɜːɡ.