Stamvader Claas Jansz: van Rensburg"s Origin
Claas Jansz: van Rensburg was the "stamvader" of the Van Rensburg’s in South Africa and he arrived at the Cape most probably 1708. He was born in 1661. His father"s name was most likely Jan or Johannes. His place of origin has not been settled. One theory is that he came from Rijnsburg near Leiden, in the Netherlands those of such an opinion Dr E Rosenthal, Dr WHJ Punt and Dr C Pama. The other theory has him coming from Rendsburg on the border between Germany and Denmark, this theory is supported by Dr J Hogeand HT Colenbrander.

Stammoeder Aletta van der Merwe"s Origin
Aletta van der Merwe was born at the Cape and was baptised 30 April 1684. Her parents were Willem Schalk van der Merwe and Elsie Cloete. Aletta thus became the "stammoeder" of the van Rensburg"s. She was previously married to Marthinus van Staden, he died in 1707, and she had three children with him:
Martha baptised 27 June 1706,
Maria 1707, married Francois Smit
Marthinus 1708, married 15 August 1728 Catharina Botha

The Family
Claas Jansz: van Rensburg and Aletta van der Merwe got married on the 14 August 1708 at the Stellenbosch church. Claas and Aletta had seven children:
b1 Johannes baptised 7 July 1709, married 27 August 1730 Anna Margaretha Botha
b2 Elsie baptised 31 July 1712, married 12 August 1731 Pieter van der Merwe
b3 Cecilia baptised 21 April 1715, married 19 April 1732 Izaak van der Merwe
b4 Willem baptised 21 November 1717, married 2 July 1740 Anna Sophia Burger
b5 Nicolaas baptised 31 March 1720, married 31 March 1743 Maria Marais
b6 Hendrik baptised 12 September 1723, married 1747 Anna Maria van der Merwe
b7 Sophia baptised 23 December 1725, married 30 November 1745 David van der Merwe

I have received the following baptism dates, but no reference to the source:
ALETTA van der Merwe was eers getroud met Marthinus van STAADE

uit welke huwelik die volgende kinders gebore is:

1704 - Die 12de Januarie is gebore Maria
1706 - Die 21ste Junie is gebore Marthinus

Uit die tweede huwelik met Jansen van Rensburg is die volgende kinders gebore:

1709 - Die 16de Junie is gebore Johannes
1712 - Die 4de Julie is gebore Elsje
1715 - Die 1ste Maart is gebore Cicilia
1717 - Die 4de November is gebore Willem
1720 - Die 16de Februarie is gebore Nicolaas
1723 - Die 20ste Junie is gebore Hendrik
1725 - Die 21ste November is gebore Sophya.

Where they Farmed and Lived
Claas and Aletta first lived on the freehold farm Vrymansfontein (Agter-Paarl), this property was purchased by Aletta"s first husband Marthinus van Staden. They then became stock farmers and had a number of loan farms:
* The loan farm Hottentotsfontein at Riebeecks Casteel was their first loan farm.
* Claas obtained another loan farm in the Land van Waveren (near Wolseley) on 17 December 1711, he called the farm Rensburg, this farm was their main place of residence
* They obtained the loan farm Groote Craal on 20 February 1717.
* They also had the loan farms Zeekoeigat (north of Wellington) on 7 May 1723,
* and Claas Voogts rivier (near Robertson) on 5 July 1724.

Civil Participation
On the 27 May 1709 Claas was appointed to the position of corporal in the Drakenstein infantry commando. On 10 February 1710 Claas was promoted to sergeant of the Drakenstein infantry and he served in this position till 1723.

Death of Claas and Aletta
Claas died prior to 6 October 1728. Aletta died 30 September 1729 and she was buried in the Drakenstein church cemetery.

SOURCES:
AM van Rensburg, "Claas Jansz: van Rensburg", Familia, 1988, Vol 25,
AM van Rensburg, "Claas Jansz: van Rensburg and his Farms", Familia 2000, Vol 37, no 4
JH van Rensburg, Die Rietvleiers: Die Familiegeskiedenis van "n Tak van die Familie van Rensburg
Unpublished paper PFS Janse Van Rensburg, "Stamboom van Barend Johannes Janse van Rensburg"
HT Colenbrander, De Afkomst der Boeren
CG de Villiers, C Pama, Genealogies of old South African Families
J Hoge, Personalia of the Germans at the Cape 1652-1806: Archives Year Book for S.A. History 1946
WHJ Punt, Collection in the Nederduitsch Hervormde Church archives Pretoria, refer to Ex Libris no 766
E Rosenthal, South African Surnames

Thanks to research by:
A.M. Van Rensburg

Family Web page:
van Rensburg Webpage