On 25 September 1846 Gustav was born in Marienburg, Mittlerer Erzgebirgskreiss,South Saxony in the eastern part of what is today Germany. He came to South Africa in 1880. He was a pastor in the Lutheran church and became a missionary in Hermannsburg, Natal, South Africa, like so many other Germans did. He married Magdalene OTTE, also from German descent in August 1883. The marriage took place in New Hanover in Natal South Africa. She was born on 28 February 1860. Gustav and Magdalene both died in Wartburg, Natal, South Africa on 26 March 1940 and 15 November 1941 respectively. Lots of possible meanings of the surname STIELAU exist but the most accepted one is “pursue a hot lead” 

CHILDREN: 

b1    Maria Magdalena *1 October 1888 x Eduard Robert WITTIG
b2    Anna Wilhelmina Catherine Elisabeth *13 July 1890 x Heinrich Christoph JOHANNES
b3    Minnie Sophia Martha *1891 x Johan Heinrich Christoph LAUTERBACH
b4    Johannes Andreas Heinrich *24 July 1893 x Katherine Marie Martha SCHUTTE
b5    Marie Magdalena Catherina *1895 x Bernhard Conrad Theodor JOHANNES
b6    Christine Martha Kathe * 1897 x Heinrich Friedrich Rudolf JOHANNES
b7    Marie Catharina Gertrud *26 October 1898 x Andreas Walter RINGELMAN
b8    Katherine Betty Charlotte Irmgard  *26 July 1900 x Wilhelm Carl Reinhard BöHMER
b9    Karl *1902
b10  Johannes Karl Gustav Adolph  *19 October 1905 x Dorothea Anna Maria KLINTWORTH 

Sources:
• MSCE ref 30595-1940
• Lutherans, Germans: Hermannsburgers 1992
• National archives
• Gedenkschrift für Gustav Adolph Ferdinand Stielau, by Hildegard Stielau 1980