Liu Peng-hua is as old as the Chinese Republic, which celebrates its 100th anniversary on Taiwan Monday, having lived through some of the most tumultuous changes in world history.

When he was born in what is today the northeastern Chinese province of Liaoning, the nation had just deposed its last emperor, many women still had bound feet, and almost all men wore their hair braided into long ponytails, or queues, stretching down their backs.

"There were no bicycles or cars in our village. Most of the time when we needed to go somewhere, we travelled on foot or rode horses or donkeys," Liu told AFP in his home near Taiwan's capital Taipei.

"Whenever I think about it, it's like a dream. So many things have happened since then. So much has changed."

The Republic of China emerged after the Qing dynasty collapsed, bringing over 2,000 years of nearly unbroken imperial history to an abrupt end, but the republic itself only lasted until 1949 on the mainland.

That year the Communists took control and the remnants of the republic, its officers and bureaucrats, moved to Taiwan, which still calls itself the Republic of China although Beijing claims sovereignty over the island.

Taiwan has more than 1,500 centenarians like Liu, while China has at least 18,000 -- men and women who have lived through a time of great historical upheaval.

The transformations that were set in motion by the fall of the empire and the rise of the republic were deep and far-reaching, said Eugene Chiu, a history professor at Tunghai University in central Taiwan's Taichung city.

"The revolution in 1911 was by no means just a political revolution. The impact was comprehensive, and it introduced western educational, legal and military systems -- even the concept of democracy -- to China," he said.

By contrast, the society Yu Chen-ping was born into in east China's Shandong province in 1907 was one steeped in ancient traditions abandoned only reluctantly.

"I kept my queue until I was 15 years old and got married," Yu told AFP at his apartment in Taipei.

At the time of Yu's birth, part of Shandong was controlled by Imperial Germany and large parts of China were reduced to the status of a semi-colony, a source of deep humiliation for the once-proud Asian power.

Fast forward to 2011, and China is again rapidly assuming the attributes of a superpower, wielding the world's second-largest economy, while enjoying expanding political and military clout far beyond its borders.

But it is development that has only come after decades of bitter strife, much of it unimaginably bloody, and much of it pitting Chinese against Chinese.

Liu and Yu fled to Taiwan in 1949, in a hasty retreat that forced both of them to leave behind their wives, because they had fought on the losing Nationalist side in a civil war that brought the Communists to power.

While the two sides have reconciled somewhat, the continued political division between them is testimony to the violence of the conflict that ended 62 years ago. And old enmities die slowly.

"My father had had dozens of acres of land, but all was stolen by the Chinese communists. You just don't know how bad they were," 100-year-old Liu said.

However, for all the political and social change that has swept across China and Taiwan over the past century, the most profound transformation may have been in the way people think.

Both societies have increasingly liberal cultures, with an ever-broadening definition of what type of behaviour most people can tolerate.

In big cities like Taipei, age-old morality is coming to an end, and open displays of affection between the sexes are no longer frowned upon. When Liu was young in the early 20th century, it was an entirely different world.

"At that time, if men and women hugged in public they risked having stones thrown at them by passers-by," said Liu, one of a dwindling number of people whose life histories offer a last link to a distant past.