President Obama, then a senator representing Illinois, walks alongside step-grandmother Sarah Hussein Onyango Obama during a visit to his ancestral village in Kenya on Aug. 26, 2006. (Radu Sigheti/Reuters)


It's the name on the tip of all of our tongues. It is whispered through the marble halls of Washington. It is shouted from the frothing mouths of protesters. Every world leader has uttered it. Obama. He may be the most-talked-about man in the world. Echoes of his unique last name bounce off the world's walls and into billions of ears.

So much has been made of President Obama's middle name, Hussein, that we almost forget about his melodic and fascinating last name. The story of how he came to have it begins, as it should, on Father's Day, with Barack Hussein Obama Sr.

Letters written by the elder Obama, but never seen by the younger one, were published Saturday in a New York Times article that documents the life of the president's father. Through the elder Obama's letters, we arrive at a picture of an ambitious and impatient man, born to poverty along the dusty roads of Nyanza province, in western Kenya, near the shores of Lake Victoria.

"I was born in a small village in Central Nyanza," he wrote in a financial aid application to American universities. "My father earned the living for the family by cooking in European homes. My mother worked on our land to help provide our food."

What neither the letters nor the article mentions, though, is that Obama Sr. was born into the Luo tribe, historically Kenya's second-most powerful after the Kikuyu. The Luos are part of an ethnic continuum of peoples stretching from Sudan to Tanzania who speak similar languages. Their population is concentrated on the eastern edges of Lake Victoria.

I spent the summer of 2010 in Nyanza province, working for the Kenya Medical Research Institute. The institute wanted to catalogue all of their patients across the region, which numbered in the hundreds of thousands. Most were Luo. One aspect of Luo culture made the cataloguing process almost impossible: the last names of the tribe's members.

Instead of inheriting a family last name, most Luos are bestowed one that reflects the circumstances of their birth, and, as such, many are extremely common.

For instance: All baby boys born at dawn are given the last name Onyango. Midnight boys get Oduor. Dusk? Odhiambo. And girls get female equivalents: Anyango, Aduor and Adhiambo.

Sets of male twins have the same last names: Opiyo for the elder, and Odongo for the younger. Opiyo (or Apiyo) would traditionally suckle his mother's right breast, and Odongo the left. Children who follow twins are given Okello, which means "to follow after."

Other Luo last names are not based on the timing of the birth but on other circumstances in that family's life. And not all of them have to begin with an O or an A, though almost all do. If the father was having a land dispute during his wife's pregnancy, and he won, the baby might be given the surname Loch, or "victory."

A final subset are ancestral names that are specific to one family. This is where we find Obama. These ancestral names are passed from generation to generation, like many European last names, but unlike most Luo last names. They often denote a defining characteristic of that family, though that characteristic may have faded with time. They begin with "O" and don't have an "A" variant.

Obama means "bent over," or "limping," in the Luo language. Some people in Nyanza say that Obama's ancestors had a specific way in which they walked, earning them this particular name. Given Obama Jr.'s above-average height and distinct stride, which he inherited from his father, it is safe to say that the namesake characteristic of the U.S. president has faded with time.

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