Johann Rockstroh was born in Erfurt, Thuringia, Prussia in 1834.
His father Johann Rockstroh was an army officer in Germany, he married Henrietta Caspari.

Johann jnr decided to leave Germany made his way to France and then to America. Here he was offered a position as doctor on a ship sailing on a botanising expedition to the South Pacific. It was not until the ship was at sea that he discovered that it was a whaler.

The ship ran on to rocks at Kerguelan Island near the Antarctic and it was six months before they were rescued. It is said that the doctor saved the crew from scurvy by making them eat the grass which grew on the island.
They were eventually taken to Hobart and it was the time of the gold rushes in Australia. Dr Rockstroh travelled to the Ovens Goldfields and Snowy River about 1860.

Then came news of gold in New Zealand so about 1865 he came to New Zealand on board the ?Aldinga?, going to Cromwell and Gabriel?s Gully. From there he moved to Hokitika and in 1866 went to Westport to take charge of the first hospital in the Nelson Province.

While on the West Coast he is said to have treated the well known pirate Bully Hayes after he was wounded in a fight.

In 1867 in Westport, on the West Coast of the South Island, he married Anna Eunice Gapper.
In 1869 he changed his name to John Frederick Rockstrow when he was naturalized.

They had 8 children, some in Westport, then they moved up to the Manawatu to Foxton and Palmerston North where John became involved with local body affairs and was elected to the first Foxton Local Board in 1875 and to the Manawatu County Council in 1878, becoming Chairman in 1882. He was a Doctor of medicine, a coroner and a J.P.

Their children were:
Frederick John Rockstrow b.1868 in Westport - d.1954 in Eastbourne, Wellington. He married Emily Francis Wilson

Henrieta Mary Rockstrow b.1869 in Wstport - d.1942 in Hamilton, Waikato. She married Charles Arbon

Rosalia Elizabeth Rockstrow b.1891 Westport - d.1942 in Palmerston North, Manawatu. She married Thomas Francis Waters.

Frances Amelia Rockstrow b.1873 in Westport or Nelson - d.1950 in Sydney, Australia. She married a Mr Brook-Taylor

Ellen Flora Rockstrow b.1876 in Foxton, Manawatu - d.1946 in New Plymouth. She married Andrew? Meuli

Augustus Isidor Rockstrow b.1878 in Foxton, Manawatu - d.1917 from wounds received in war in BELGIUM - buried Lijssenthoek

William Caspari Rockstrow b.1881 in Foxton, Manawatu - d.1909 in Palmerston North. He was 28 and unmarried

Walter Leonard Rockstrow b.1883 in Foxtonw, Manawatu - d.1961 in New Plymouth. He married Catherine Clara Groombridge.