There was no stopping Scottish explorer David Livingstone.

In March 1866, he embarked on what would become his greatest journey. After a lifetime of exploration, he began his search for the headwaters of the Nile River.

After 25 years of exploring Africa, Livingstone set out excited to continue doing what he loved.

"The mere animal pleasure of traveling in a wild, unexplored country is very great," he wrote. "No one can truly experience the charm of repose unless he has undergone severe exertion."

That sentiment — never stop — summed up a man obsessed with new horizons.

Five years later, after multiple presumptions in Great Britain of his death and innumerable hardships in Africa, he was greeted in the village of Ujiji with the now-famous (if historically disputed) greeting, offered by journalist Henry Stanley, "Dr. Livingstone, I presume?"

It capped a life of exploring that led Livingstone (1813-73) to discover a million miles of land. He was the first European to complete a journey across Africa.

Livingstone's entire life was based on obsessively searching out the next uncharted vista.

To The Fore

When leading an expedition, he preferred to take the lead and scout the trail ahead.

He distrusted decisions by committee. He deplored what he called the "envy and backbiting" displayed by some of his fellow missionaries.

He preferred to dodge danger without regard for others' opinions.

"When trouble came, Livingstone would sidestep it and move forward. Always forward," wrote Martin Dugard, author of "Into Africa: The Epic Adventures of Stanley & Livingstone."

Trained as a missionary, Livingstone was defined by two traits: optimism and idealism.

He won few converts in his missionary travels during his first 15 years among the natives up to 1856. But the experience never fazed him. He simply put on his explorer hat and studied the land. Such talent led him to discover Victoria Falls, which he named after his queen.

His exploits made him famous and rich in Britain after his "Missionary Travels and Researches in South Africa" became a best-seller. He was so hooked on Africa that he kept returning in any capacity he could.

He became obsessed with opening the Zambezi River to trade. He believed the spread of trade would lift Africa out of poverty and put an end to the slave trade.

He tried to navigate the river in leaking steamships. After a six-year expedition fraught with desertions, he was left nearly alone on the east African coast.

Instead of giving up, he mounted his next voyage. To his few remaining colleagues' amazement, Livingstone hopped on a small ship and sailed 2,500 miles across the Indian Ocean from Zanzibar to Bombay.

His desire to keep moving motivated him to embark on what was a highly dangerous voyage. He beat the start of monsoon season by days.

"The . . . fact remains that without his overoptimism . . . Livingstone would never have crossed Africa and would certainly never have been able to summon up the superhuman tenacity and endurance which had alone kept his deeply divided and disillusioned expedition in being," said Tim Jeal, a Livingstone and Stanley biographer.

His travels took a physical toll. Livingstone suffered from hookworms and anemia.

In early 1844, his left arm was left permanently twisted after an attack by a hungry lion.

"Growling horribly close to my ear, he shook me as a terrier dog does a rat," he wrote.

He said the encounter left him with little fear of death.

He also endured severe privation. He even scrounged for rats to eat along the jungle floor.

Malaria, smallpox and dysentery were constant companions on his expeditions, and he suffered dozens of bouts with fever.

Livingstone's idealism sustained him through it all.

He saw economic trade as the key to lifting Africa's people out of poverty, and believed Africa's leaders needed commerce and Christianity.

In his early dealings with Africans, he focused less on preaching and more on advising them on agricultural and technical matters.

That gained trust among the locals, who allowed him access to their versions of processes like iron smelting, which no other European had seen.

He wrestled with the negative impact of aggressive colonialism. But Livingstone firmly believed in property rights and ownership. He believed Western-style capitalism could provide Africa with the same advantages as industrial England.

Yet Livingstone was among the earliest to recognize the difficulties of altering African societies. Reluctant converts in Africa, he saw, were facing new ideas that challenged their social structures.

He respected that. Others simply wrote off the natives as lesser beings. Livingstone would continually reject such racist stances, including in his staunch opposition to the slave trade.

In 1865 he told fellow explorer John Kirk, "The slave trade must be suppressed as the first great step to any mission — that baffles every good effort."

At times Livingstone seemed to prefer his adopted people to his European brethren. He remarked that Africans "showed more intelligence than is to be met with in our own uneducated peasantry."

His opinion of home was formed during a difficult childhood.

Livingstone's first voyage didn't set sail until he was 27 years old.

His upbringing was a far cry from taming the wilds of Africa, but it was rough in other ways.

Born and raised in a Scottish mill town, his family of seven shared a single room in a tenement house.

His father sold tea. Young David and his brothers worked long hours in the cotton mills to make ends meet. Fourteen-hour days began at dawn, six days a week.

Push To Learn

David was a self-starter on the education front. He joined a small fraction of students who attended classes for two hours a night after the factory whistle blew.

He attacked his education with the same passion that would drive his exploration.

At age 13, he learned Latin. He would often read late into the night before rising to start the next factory shift at 6 a.m. He spent off hours studying botany and geology texts.

That dedication led to medical training and earned him the chance to travel as a missionary. It also won him the hearts of many Africans.

After being found by Stanley, Livingstone chose to remain in Africa.

He continued to explore rivers he hoped would lead him to the Nile. But his health was failing, and he died in 1873, probably from dysentery or malaria, in a village 70 miles southeast of Lake Bangweulu in what now is Zambia.

He never found the Nile's origins.

In 1874, Livingstone was interred in London's Westminster Abbey.

BY KIRK SHINKLE