There have been big victories in the battle for women's rights. Here in Britain we've made enormous progress in the last 150 years since the MP John Stuart Mill first tried to get Parliament to give women the same political rights as men.
But let's be clear: it's all still taking far too long. The pace of change has not been fast enough - and that's what we need to keep at the forefront of our minds this International Women's Day if we are to achieve the acceleration in progress for women that we want and so badly need.
Across the world girls' opportunities in life are curtailed long before they reach adulthood, simply because they are a girl. That's just plain wrong. I believe women's rights are the greatest unmet human challenge of our times, but I also passionately believe it's a challenge we can meet in the coming years.
Since taking on the role of International Development Secretary in 2012, I have made it my priority to transform the lives of the poorest girls and women around the world. It truly is at the heart of anything my Department does and while there is undoubtedly a long way to go until we have true equality, I am incredibly proud of what we've achieved, working alongside others, so far.
In 2014 we held the first ever Girl Summit event in London, aimed at ending child marriage and Female Genital Mutilation (FGM) within a generation. Since then six countries with high levels of child marriage; Bangladesh, Burkina Faso, Ghana, Mali, Yemen and Zambia, have begun action to end this serious violation of human rights. The UK is providing £25 million to drive these changes forward and is helping to strengthen the law across countries where child marriage is most prevalent, with the potential to reach around 2.5 million girls at risk.
Last May, Nigeria took the historic step of banning FGM, followed in November by The Gambia. Egypt and Kenya already have laws in place and are now upping their game to ensure they lead to more arrests, which can act as a vital deterrent. FGM is nothing short of an extreme form of violence against women and girls and the UK has pledged £35million to support the fight against this terrible practice.
I am proud that the UK has been able to play a role in making sure these issues are now being talked about and being dealt with, shining a light on what remain difficult issues. It is just as important that over the last five years we have enabled almost 10 million additional women to use modern methods of family planning and supported more than five million births with the help of trained medical professionals.
One of the most important things we can do for any young person is to educate them. The UK has helped over five million girls get a decent education in the last five years through training 190,000 teachers, building classrooms and ensuring the poorest girls and boys have school bursaries and textbooks. But this is still not enough - over the next five years we will help 6.5 million more girls go to school, stay in school and learn. This will lead to higher wages and more opportunities, as well as meaning they're less likely to marry young and have children early. An education transforms a girl's life.
Quite simply, no country can develop if it leaves half of its population behind. Investing in girls' education, reproductive health, women's economic empowerment and tackling violence is one of the best strategies for eradicating poverty and boosting economies - including our own in the UK. Girls and women everywhere need control over their lives - the power to make their own choices about their health, their marriage, their family, their education and their careers. That is why we will continue to put improving the lives of girls and women at the heart of everything we do.
It took sixty years after John Stuart Mill's petition to Parliament for women to get the vote here in Britain. In this century let's turbocharge the pace of change on girls and women's rights. Women and the world cannot afford to wait.
Justine Greening is the Secretary of State for International Development, and Conservative MP for Putney
HuffPost UK is running a month-long project in March called All Women Everywhere, providing a platform to reflect the diverse mix of female experience and voices in Britain today. Through blogs, features and video, we'll be exploring the issues facing women specific to their age, ethnicity, social status, sexuality and gender identity. If you'd like to blog on our platform around these topics, email ukblogteam@huffingtonpost.com with a summary of who you are and what you'd like to blog about