The story of the Millennium Development Goals agreed in the year 2000 has a touch of the fairy tale about it; absolute poverty halved, 50 million more children in school, 14,000 fewer child deaths each day. Magic. The story and its statistics are, rightly, a much loved development achievement.
But equally compelling is the less reported tale of the past 15 years; billions of people left behind, masked inequalities and growing gaps between rich and poor.
Today, a child born in the region of Niger with the highest mortality rate is five times more likely to die before their 5th birthday than if born in the region with the lowest rate - an inequality that has doubled since 2008.
In Peru, a child living in the remote Andean area of Huancavelica is eight times more likely to be physically stunted than a child in the capital city, Lima.
Around 84% of richest young men in the Littoral region of Benin completed primary school in 2006, compared with only 1% of the poorest women in the Alibori region.
So the unabridged story; Millennium Development Goal progress is unprecedented, but also unequal.
At Save the Children, we believe that life chances shouldn't be determined before birth. We know inequalities are not an inevitable outcome of development. And now, we're focused on redressing the balance - ensuring that the Framework that will replace the Millennium Development Goals leaves no one behind.
'Leave no one behind' is fast becoming the mantra of the new Sustainable Development Goals, to be launched in September. This is hugely encouraging, but it's also fairly abstract. So, in addition to the soundbite there needs to be a focus on the substance - locking-in a concrete commitment to ensure that 'no target is considered met unless met for all social and economic groups'.
That people's outcomes in life shouldn't be determined by their income, gender, age, race, ethnicity, disability or geography is a truly transformative notion that could shift the course of global development - for good.
But it's also a tall order. In September this year, Heads of State will sign off a new Sustainable Development agenda, which, in its current form, includes 17 universal Goals and 169 Targets (compare that with the eight Goals and 21 Targets of the Millennium Development Goals). A commitment such as 'leave no one behind', that cuts across all goals and targets, represents a major monitoring challenge. But that is part of its potential, providing an accountability angle and demonstrating a normative shift in how we 'do development'. This commitment, and our ability to hold governments to account for its delivery, flag that the rules of the game are changing.
And it's gaining momentum; recently, 3,200 organisations from across six continents called for the criteria of 'no target met, unless met for all' to be mainstreamed into the MDGs successor Framework. Subsequently, the UN Secretary General's Report - The Road to Dignity- explicitly referenced this as a guiding principle.
Negotiations in New York last week, on the Declaration that will set the vision for development over the next decade and beyond, also locked-in this language, though its position in the final agenda is far from secure.
No doubt such a radical suggestion - that we measure success not by what we achieve for some, but what we achieve for all - is likely to face resistance the closer we get to finalising the Framework. But as the agenda's single most transformative commitment, we must continue to advocate for its declaration in 2015 and its delivery through to 2030.
Coupled with a commitment to put those furthest behind first and invest in countries' capacity to generate and make available timely and reliable data, 'no target met, unless met for all' has the potential to be one of the lasting legacies of the Sustainable Development Goals.
As the lever to end the lottery of birth - for the child in Andean Peru, the poorest regions of Niger or rural Benin and the hundreds of millions more steadfastly stuck at the bottom of the ladder - governments and the wider development community must recognise the opportunity and the responsibility that drafting the new development Framework represents - to ensure that 'no target is considered met unless met for all'.
Alone it won't deliver the 'happily ever after', but it will move us a major step closer to a more equitable ending to our shared story of development.