Taiwan's gay couples display their wedding certificates after registering in Taipei. (AFP)

Taiwan made history on Friday with Asia's first legal gay weddings as same-sex couples tied the knot in jubilant and emotional scenes, the culmination of a three-decade fight for equality.

The weddings, which came a week after lawmakers took the unprecedented decision to legalise gay marriage despite staunch conservative opposition, places Taiwan at the vanguard of the burgeoning gay rights movement in Asia.

Some dozen couples were among the first to arrive at a government office in downtown Taipei to legally register their relationships as marriages.

They embraced and kissed in front of the gathered press before proudly holding aloft their wedding certificates as well as new identity cards listing each other as spouses.

Among those tying the knot were social worker Huang Mei-yu and her partner You Ya-ting.

They held a religious blessing conducted by a progressive Buddhist master in 2012 but they longed for the same legal rights granted heterosexuals.

"It's belated, but I'm still happy we can officially get married in this lifetime," Huang told AFP after signing her marriage certificate, clutching a bouquet and beaming.

Legal recognition of their love, she said, was a crucial step and might help others accept their relationship.

"Now that same-sex marriage is legally recognised, I think my parents might finally feel that it's real and stop trying to talk me into getting married (to a man)," she said.

Shane Lin and Marc Yuan, a couple who fell in love at college, were the first to register.

"It's not been an easy journey and I'm very lucky to have the support of my other half, my family and friends," Lin told reporters through tears.

"Today I can say in front of so many people that we are gay and we are getting married. I'm really proud that my country is so progressive," he added.

Long fight for equality

Taiwan made history last week when it became the first place to legalise gay marriage in Asia, home to 60 percent of the world's population.

But the issue has also caused deep divisions on an island that remains staunchly conservative, especially outside of the cities and among the older generation.

Some 300 same-sex couples are expected to register on Friday, according to local authorities, around 150 in the capital Taipei which boasts a thriving and vocal gay community.

The city hall will co-host an outdoor wedding party near the famous Taipei 101 skyscraper, with local and foreign dignitaries expected to attend.

For veteran gay rights activist Chi Chia-wei -- dressed in an eye-catching red suit with a rainbow headband -- Friday's registrations were the culmination of a three-decade fight trying to persuade successive governments to change the law.

It was Chi who eventually petitioned Taiwan's Constitutional Court leading to a 2017 judgement that denying same-sex couples the right to marry was unconstitutional.

Facing an imminent court deadline, parliament finally passed a bill last Friday allowing same-sex couples to form "exclusive permanent unions" and another clause that would let them apply for a "marriage registration" with government agencies.

"I feel very happy that same-sex couples can finally register and be listed as each other's spouse. I am honoured to witness Friday's marriage registrations," he told AFP.

Conservative pushback

In the last decade Taiwan has become increasingly progressive on gay rights with Taipei hosting by far Asia's largest pride parade.

But the issue has polarised society.

Conservative and religious groups mobilised after the court ruling and comfortably won a series of referendums last November in which voters comprehensively rejected defining marriage as anything other than a union between a man and a woman.

Conservative lawmakers put forward rival bills that offered something closer to limited same-sex unions but those measures failed as parliament comfortably passed the gay marriage law.

However, the new law still contains restrictions not faced by heterosexual couples.

Same-sex couples can currently only adopt their partners' biological children and can only wed foreigners from countries where gay marriage is also recognised.

Gay rights groups say they are willing to accept partial equality for now in the hopes of winning later legal battles over issues such as adoption, surrogacy and marrying foreigners.

Opponents have vowed to punish President Tsai Ing-wen and the lawmakers who supported the gay marriage law at January's elections when Taiwanese will elect both a new president and a new parliament.