English naval officer, surveyor and meteorologist, direct descendant of Charles II, Fitzroy graduated with distinction from the Royal Naval College at Portsmouth and joined the Royal Navy (1819). His rise to scientific fame begins with an appointment to commander of HMS Beagle (1828-1836) during an expedition led by P.P. King of HMS Adventure, charged with surveying the coasts of Patagonia and Tierra del Fuego (1826-1830). Fitzroy succeeded Pringle Stokes who had committed suicide following the stress of months of gales, sickness, death and depression at the prospect of returning to the survey. Fitzroy would later be captain of HMS Beagle on its famous circumnavigation (1832-1836), accompanied by a young Charles Darwin. Though Fitzroy was more concerned with science than were many naval officers of his day and aided his accompanying naturalists, there are no specimens directly attributed to him. Material from this expedition is not attributed to individuals, a common practice of the time. However, the official orders issued to P.P. King for the expedition stated "you are to avail yourself of every opportunity of collecting and preserving specimens of such objects of natural history as may be new, rare, or interesting; and you are to instruct Captain Stokes, and all the other officers, to use their best diligence in increasing the collections in each ship, the whole of which must be understood to belong to the public."

Since the official collector, James Anderson, was on the Adventure and the two vessels were apart for months at a time, Fitzroy and his officers must have been part of the collecting process in order to fulfil their orders. The official account of the voyage includes many first-hand botanical observations made by Fitzroy, who was often part of the shore exploration. Both Bynoe, assistant surgeon and Midshipman J.L. Stokes go on to make plant collections in Australia during later surveying voyages of the Beagle.

All of the collections from the surveying voyage of 1826-1830 were provisionally deposited with the British Museum by P.P. King on return from the expedition, with a permanent deposition in the national collections at BM made in 1845. In a private letter to Charles Darwin dated 20 Jun 1839, Fitzroy criticised Robert Brown for his tardiness in dealing with the specimens, considering that he had "mistreated" King by holding back the specimens for nine years. Publicly in a preface to King's published account of the first voyage, Fitzroy wrote "it may be a subject of regret, that no paper on the Botany of Tierra del Fuego is appended to the first volume. Captain King took great pains in forming and preserving a botanical collection, aided by a person embarked solely for that purpose. He placed this collection in the British Museum, and was led to expect that a first-rate botanist would have examined and described it; but he has been disappointed".

Fitzroy entered politics and became Tory M.P. for Durham (1841-1843); he was later appointed Governor of New Zealand in 1843 but recalled in 1845 because of his humanitarian beliefs regarding Maori land claims. In England again he was given a shore posting as Superintendent of the dockyard at Woolwich (1848-1850), until his retirement from active service.

His scientific achievements in surveying and meteorology were finally recognised and he was elected a Fellow of the Royal Society (1851). He advised the government to establish a meteorological office and was made Chief (1854-1865) of the meteorological department at the Board of Trade, later the world's first Meteorological Office. Fitzroy promoted the use of meteorology to help save lives in shipping and invented his own versions of the 'Fitzroy barometer'; he supported development of the lifeboat institutions and invented the concept of a 'weather forecast'. In 1860 The Times became the first newspaper in the world to publish a daily weather forecast, prepared by Fitzroy. However Fitzroy was a deeply troubled individual. He found it difficult to handle public criticism of his meteorological methods and humanitarian convictions, and to reconcile his strongly-held religious beliefs with the theories of his erstwhile friend Charles Darwin. At the famous debate on evolution at Oxford (1860), he was evicted from the building for heckling T.H. Huxley, brandishing his Bible and shouting "here is the truth - in here!". Passed over for an important post by the navy, a perfectionist who chose not to live with perceived imperfections, he committed suicide at his home at Upper Norwood on 30 April 1865 by cutting his throat.

There is little remaining of his botanical legacy, though a small number of important specimens collected by his officers and naturalists exists at BM. Based on a remarkable conifer that he had reported from Chile, capable of growing for over 3,500 years (the second oldest tree ever recorded), the genus Fitzroya Hook. f. was named in his honour.