One incredibly long church aisle

"There are many Africas. There are as many Africas as there are books about Africa - and as many books about it as you could read in a leisurely lifetime. Whoever writes a new one can afford a certain complacency in the knowledge that his is a new picture agreeing with no one else's, but likely to be haughtily disagreed with by all those who believe in some other Africa." The quote is from West with the Night by Beryl Markham, and it is very apposite to the writing of another early British settler of Kenya, Ewart Grogan, the extraordinary, imperious subject of this exceptional biography.

Born in Britain in 1874, and heavily influenced by the adventure novels of Rider Haggard, Grogan came to national prominence by becoming the first man to travel the length of Africa, south to north, from the Cape to Cairo - a three-and-a-half year journey that won him the hand of his bride.

Earlier, he had endured a schooling at Winchester College, and been sent down from Jesus College, Cambridge, for herding sheep into his tutor's rooms. He climbed the Matterhorn and after an aimless few months, sailed for Cape Town in 1896 where he was immediately given the task of running a wagon-load of ammunition up to Bulawayo in Southern Rhodesia. After making a successful delivery, he signed up as a member of the Matebele Mounted Police.

He had his first taste of dysentery and malaria, but his successful exploits got him transferred to Cecil Rhodes's personal escort. Here, around the evening campfire, Grogan fell under the spell of the great colonial pioneer as he first heard of Rhodes's vision of civilising an African continent by building a railway and telegraph system up the entire length of Africa.

After a serious bout of blackwater fever and a discharge from the campaign, Grogan drifted into Portuguese East Africa where, in self defence, he accidentally killed a man. He was smuggled to safety on board a German ship bound for Zanzibar and eventually made his way back to England, and there met the beautiful Gertrude Watt, whose father and stepfather were men of considerable means. They fell in love and discussed marriage; but Grogan had little future and no resources. Confronted with this by Gertrude's stern father-in-law, he determined to prove his fitness by becoming the first man to journey from the Cape to Cairo.

Departing Britain in January 1898 with a single companion, Harry Sharp, Grogan sailed to Africa and then set off from Beira north towards the Rift Valley lakes of Nyasa (today's Lake Malawi) and Tangan-yika. The historic journey had begun. Grogan, Sharp, five Watonga tribesmen, ten armed Asiskas and 150 Manyema porters headed into the unknown. Before returning to England in 1900, Grogan had survived dangerously high malarial temperatures; become the first white man to see Lake Kivu; surveyed the east coast of Lake Edward; skirted the 15,000ft snow-capped Ruwenzori Mountains; survived attacks from Dinka tribesmen and Balecka cannibals from the Congo; and reached the Uganda border (where Sharp and the Manyema porters left the party).

A starving Grogan and his remaining men survived by eating pelicans and marabou storks. Constantly sick, he somehow travelled through the almost-impenetrable Sudd in the southern Sudan, which he described as "a desolation of desolations, an infernal region, a howling waste of thorn and stones - waterless and waterlogged". But eventually he reached Khartoum (where the Blue Nile meets the White Nile) and Omdurman from where he finally took a succession of steamers and trains to Cairo. He was just 25 years old, and following the publication in 1900 of From the Cape to Cairo , Grogan became the youngest man ever to address the Royal Geographical Society and the toast of England. He and Gertrude were married later that year.

Restless as ever, Grogan returned to Africa and became one of the most powerful figures in the development of the newly established colony of Kenya. He acquired 1.6 million acres of land, which he developed for forestry, and had the Mombasa-Kisumu railway diverted to run through his property. By the time he died, Grogan had turned Mombasa into Africa's first deep-water port and built Nairobi's finest hotel (The Torrs) and the best children's hospital in Africa opposite his favourite Muthaiga Club, besides founding Kenya's fledgling timber industry. Grogan's Castle can still be seen on a high point southeast of Kilimanjaro overlooking thousands of acres of flourishing sisal plantations.

Local Kikuyu tribesmen called Grogan "Bwana Chui" (the leopard). He certainly had his vicious, macho side. When Gertrude was apparently molested, Grogan took the law into his own hands, publicly whipped three rickshaw drivers in front of the Nairobi courthouse, and was subsequently imprisoned for a month. He also maintained three families and fathered six daughters by three women. Nevertheless, Gertrude loved him with tolerance until her death in 1943.

Like the mesmeric Victorian explorer Sir Richard Burton a century before him, Grogan lived his life in search of new challenges to conquer, some of which were unattainable. Adventurer, patriot, soldier, visionary, lover and rogue, Grogan always believed in the Empire. Some of his achievements are legion yet when he died in 1967, The Times did not rate Grogan worthy of an obituary.

Edward Paice has filled that gap and produced a marvellous story. Such is his passion for his subject that he sacrificed a promising merchant banking career in the City to concentrate on the book. Having myself just returned from east Africa, and endured a 4,400-mile journey researching Hemingway's two eventful safaris there in 1933 and 1953, I can testify that Grogan's achievements and legacies are ever present.

Christopher Ondaatje is a council member, Royal Geographical Society, whose most recent two books deal with the explorer Sir Richard Burton.