In 1871 Bendix Hallenstein and his wife Mary purchased land at Speargrass Flat for his country estate. He built a large homestead and called the property Thurlby Domain after his wife's family home in Lincolnshire, England.
The land was subsequently transferred to Herman Arndt, a friend and colleague of Hallenstein’s, in 1875. The story of the tree goes; while traveling the Holy Land, Hallenstein collected a cone from one of the cedars in Lebanon and sent it to Mrs Arndt who planted one of the seeds in front of the homestead (Millar, 1962).
This story and subsequent tree that arose from this cultivation has even prompted poetic reference by one of New Zealand’s significant literary figures and Hallenstein’s great-grandson, Charles Brasch;
All his; and he in Lebanon plucked the cone
From which that masterful cedar sprang alone; (Brasch, 1957).
The tree was considered to be the tallest of the species in New Zealand in 1984 (Burstall & Sale) and is still the tallest on record to date Cadwallader, 2013).

References.
1) Bendix Hallenstein, Biography. Te Ara - Online Encyclopedia of NZ
2) F.W.G. Miller, Golden Days of Lake County, Christchurch, Whitcombe and Tombs, 1962
3) Charles Brasch, ’Letter from Thurlby Domain To Colin Newbury’, from The Estate and other poems [1948-1952], Christchurch, Caxton Press, 1957.
4) New Zealand Historic Places Trust, Registration Report number 2240.
5) Burstall & Sale, Great Trees of New Zealand, 1984.