Dynasties have long been a feature of the politics of Asia: sons, daughters and spouses inheriting famous names and faces, as well as political legacies to uphold, improve or destroy.

In a part of the world where literacy rates are low, where parties build ever-loyal ''vote banks'' through subsidies and pork-barrelling, and where personality is often more influential than policy, a famous last name is disproportionately influential.

This weekend, Pakistan goes to the polls for an historic election, marking the first time a government in that country has served out its term without being derailed by a coup or assassination.

For the ruling Pakistan People's Party, prominent throughout the campaign has been Bilawal Bhutto, the young prince of the famed, but ill-starred Bhutto dynasty.

He is grandson of the party's founder and former president Zulfikar Ali Bhutto, who was hanged by the general who displaced him in a coup. His mother, Benazir Bhutto, was twice prime minister before being assassinated by a suicide bomber in 2007. His father is Asif Ali Zardari, the ruling President.

Though Bilawal Bhutto, a few months short of the 25-year age cut-off, is too young to stand for office, he announced his entry into Pakistani politics late last year with a fiery speech at his family's mausoleum.

On the fifth anniversary of his mother's assassination, he took aim at his party's perceived enemies, in the Supreme Court, in the military, and in the shadowy bands of extremists whose violence still threatens to derail democracy in Pakistan.

In highlighting his family's sacrifices, he underlined the influence of his name in Pakistan politics.

''Every challenge is soaked in blood, but you will be the loser. How ever many Bhuttos you kill, more Bhuttos will emerge from every house.''

Bhutto has been on the hustings these past weeks, but to most Pakistanis he remains an enigma. For safety reasons he is rarely seen in public, and he has spent most of his life outside the country. After years studying law at Oxford, he speaks with an English accent and his Urdu is variously described as ''hesitant'' or ''good but not flawless''.

He almost never grants interviews, and has not responded to criticism over the building of ''Bilawal House'', a massive mansion on the outskirts of Lahore, rumoured to cost more than $90 million, fuelling allegations he is out of touch with poor Pakistanis.

Nonetheless, there is already talk a byelection will be engineered next year (after his 25th birthday) to bring him into parliament, and even discussion of the young Bhutto as leader. ''The PPP owes its strength to the Bhutto name,'' party spokesman Farhatullah Babar says obliquely in discussion of his future.

Political analyst Dr Hasan Askari Rizvi says Bhutto's ascension is almost preordained.

''The ultimate goal of the PPP is that Bilawal takes control of the party and the country, but it will take time for him to demonstrate his ability to lead. He will likely be prime minister, but … it will be a long time.''

Powerful dynasties are not a feature unique to South Asian politics. The US has its Kennedys and Bushes and Clintons, Europe's monarchies have given way to its Le Pens, de Gaulles and, latterly, Milibands. Even Australia, to a lesser extent, has its Downers, Cains, Beazleys and Creans.

But dynastic succession has found its most fertile, and resilient ground in south Asia, for several compelling reasons.

Politics, as any list of assassinations in the region reflects, is a brutal game in south Asia, and loyalty is a rare commodity.

Family can (usually) be relied upon to be staunch, and won't defect or usurp for material gain.

Outside cities, literacy rates remain low, and a recognisable name can be a decisive factor in swaying millions of votes.

With vast, rural, poor populations, many elections in south Asia are reduced to subsidy-based vote-bank politics, where swathes of votes are essentially ''bought off'' with promises of cheaper fuel or food. A vow to uphold, or improve, a forebear's pledge is worth votes. And in elections where there is often little ideological difference between the parties, the importance of personality is further strengthened.

''In the villages of Pakistan, whole families, whole villages, their votes belong to a certain party or family,'' Abdul Razzaq Chishti, editor of the Urdu-language newspaper Daily Ash-Sharq, says.

''They all vote the same way, maybe because a politician visited and made a promise, maybe because the man at the head of the family tells them, maybe just because they always have. It can be very hard to change.''

But perhaps the enduring strength of dynasties here lies in the simple fact that a powerful background brings opportunity.

In societies where the gap between rich and poor is massive, the political process is closed to all but a chosen few.

A political pedigree is an instant entree, sometimes all the head-start a young politician needs.

''In the initial stages, these dynasties provide continuity and stability,'' Dr Rizvi says, noting that, in times of tumult, too, voters turn to ''trusted brand names'' for a sense of certainty, however illusory.

But, too often, the products of dynastic succession bear ill for the country: political stagnation, corruption, and further nepotism, governance only to secure the next generation's place.

''As long as each generation is fairly elected, and the people have a democratic right, it can be a positive thing, but if the democratic process is disrupted, or people are kept out of participating fully, it is definitely negative.''

Five south Asian countries go to elections this year, followed by India next year and Sri Lanka in 2016. Famous families will dominate. In Bangladesh, the women who lead the main political parties to elections later this year - Sheikh Hasina of the Awami League and Khaleda Zia of the Bangladesh Nationalist Party - are the daughter and widow, respectively, of two of Bangladesh's most famous leaders. Both women have served as prime minister.

The Rajapaksa family will be preeminent in Sri Lankan politics for years to come, even if the constitution prohibits President Mahinda Rajapaksa from standing again in the 2016 poll. Already, he and his three politician brothers have direct control over 70 per cent of Sri Lanka's budget, and he is grooming his parliamentarian son Namal for greater honours.

Nepal has elections this year, as does Bhutan for only the second time. Both have family connections running through their main parties.

In the Maldives, due to go to the polls in September, President Mohamed Waheed - who snatched power in a controversial police-backed action (a coup in all but name) - has brought into his cabinet the daughter of former dictator Maumoon Gayoom, who is also Waheed's patron.

In Myanmar, Aung San Suu Kyi, daughter of revered revolutionary General Aung San, is perhaps the world's most famous political progeny. Widely regarded as the leader of the Myanmarese people, she has, after years under house arrest at the hands of the country's junta, taken her place in parliament.

But if the family business is running the country, what if the chosen one chooses not to mind the shop?

In India, one family has dominated politics since the modern country came into being.

The long haul to next year's elections has started, and, on the side of the ruling Congress party, eyes are again turned to the 41-year-old scion of the Nehru-Gandhi dynasty. If - many in India would say ''when'' - Rahul Gandhi becomes prime minister, he will be the fourth generation of his family to hold the post.

Gandhi has been a parliamentarian for almost a decade and was last month elevated to the vice-presidency of the Congress party.

But, compared with the firebrand, and significantly younger, Bhutto across the border, Gandhi has appeared a listless politician. Commentators regularly opine he appears to be in politics out of a sense of duty to his powerful family, rather than a passion for the vocation itself.

Gandhi spearheaded the Congress' campaign in the state elections in Uttar Pradesh, but his party lost badly to the Samajwadi Party led by Akhilesh Yadav (himself a political offspring, his father was chief minister of the state three times). Yadav's sharper tactics, riding his bicycle from village to village campaigning, trumped Gandhi's program of set-piece rallies and predictable speeches.

This year Gandhi made a rare, and, in the context of his prominent role in India's slow-burn election campaign, curious, statement, the type of which must be anathema to dynasties all over the world.

The boy king of India, regularly described as the country's prime-minister-in-waiting, said he didn't want the job. ''My priority is not to become the prime minister … have no lust for power or to become the PM,'' Gandhi said.

Such candour may be in India's - in any dynastic country's - best interest. A true democracy must be more than one family's fiefdom, Dr Rizvi argues. ''In the long run, the institutions need to be strong, the process needs to be strong, stronger than one family.''