Senenmut was born at Iuny, the town the Greeks called Hermonthis and modern Egyptians call Armant, about thirty kilometres south of Thebes on the west bank of the Nile. His father was Ramose and his mother was Hatnofer, commoners of no particular rank who may already have been in the service of Queen Ahmose, the mother of Hatshepsut. Senenmut began his career as a soldier, distinguishing himself in three campaigns against Nubia, the land south of Elephantine where the Nile narrowed between granite cliffs and the desert people resisted Egyptian control. His military service gave him the discipline and the connections that would launch his meteoric rise, but it was his intellect and administrative genius that carried him from the battlefield to the palace.

By the time Hatshepsut ascended the throne - first as regent for her stepson Thutmose III, a child of two or three years old, and then as pharaoh in her own right, crowned with the false beard and nemes headdress of a king - Senenmut was already one of her most trusted servants. His titles multiplied with bewildering speed: Steward of the God's Wife, Steward of the King's Daughter, Overseer of the Granary of Amun, Overseer of Works, Chief Architect, and eventually Great Treasurer of the Queen and Director of all Royal Works. He managed the queen's estates, supervised her quarries, and coordinated the labour forces that built her temples from Aswan to Karnak. On a statue now in the Egyptian Museum in Berlin, he had himself inscribed with words of astonishing confidence: "I am a noble, loved by my lord, and have entered into the opinion of the Lord of the Two Lands. He made me become the Grand Administrator of his House and Judge of the whole country. I was above the great, Director of construction managers."

The defining achievement of Senenmut's life was the mortuary temple of Hatshepsut at Deir el-Bahri, a site on the west bank of the Nile near the entrance to the Valley of the Kings. The temple, called Djeser-Djeseru, was built in three vast terraces rising against the cliffs, each terrace supported by colonnades of square pillars and connected by grand ramps that ascended from the valley floor to the sanctuary at the top. The design was inspired by the earlier temple of Mentuhotep II, a king of the Eleventh Dynasty who had reunified Egypt after the chaos of the First Intermediate Period, but Senenmut transformed the older model into something entirely new: a temple of perfect symmetry and proportion, its white limestone walls once painted in brilliant colours, its gardens planted with trees and flowers brought from the queen's trading expeditions to the land of Punt. The focal point was the sanctuary of Amun, the king of the gods, where the divine barque of Amun would rest during the annual Beautiful Festival of the Valley, but the temple also celebrated Hatshepsut's divine birth, her military campaigns, and her trade with foreign lands. Senenmut's own name appeared in the temple's inscriptions, a rare honour for a non-royal man that testified to his unique position at court.

At Karnak, Senenmut supervised the quarrying, transport, and erection of two obelisks of pink granite from Aswan, the tallest ever raised in Egypt at that time. One still stands today, the tallest ancient obelisk in the world at nearly thirty metres, while the other lies in fragments on the ground, having toppled centuries ago. He also built the Red Chapel, or Chapelle Rouge, a barque shrine of red quartzite that may have originally stood between the two obelisks and that was decorated with reliefs showing Hatshepsut offering to Amun and performing the rituals of kingship. The chapel was later dismantled by Thutmose III, the stepson whom Hatshepsut had pushed aside, and its blocks were reused in other buildings, but modern archaeologists have reassembled many of them, and the vivid red stone still bears the painted images of the queen and her architect.

Senenmut's relationship with Hatshepsut's family was intimate as well as official. He was appointed tutor and foster father to Neferure, the queen's only child, a daughter born to Hatshepsut and her husband Thutmose II before the latter's early death. Block statues show Senenmut seated with the princess on his lap, her tiny figure wrapped in his cloak, a pose that suggests a genuine affection and a role as surrogate father. Some Egyptologists have speculated that Senenmut and Hatshepsut were lovers, citing his unprecedented access to the queen, his burial beneath her temple, and the erasure of his name from some monuments after her fall, but there is no direct evidence of a romantic relationship, and others argue that his devotion was simply the loyalty of a man who owed everything to his patron. What is certain is that Neferure died young, probably before reaching adulthood, and that her death may have marked the beginning of Senenmut's decline.

Senenmut prepared two tombs for himself, a luxury that only the most powerful officials could afford. The first, TT71, was built in the Tombs of the Nobles at Sheikh Abd el-Qurna, the standard burial ground for high officials on the west bank of Thebes. It was decorated with reliefs showing Senenmut in his various roles, but it was never completed and he was apparently never buried there. The second tomb, TT353, was something entirely different: a secret hypogeum carved into the rock beneath the very courtyard of Hatshepsut's temple at Deir el-Bahri, accessible only through a hidden entrance and descending forty-one metres into the bedrock through a stepped corridor. The tomb was never finished - the walls of Chamber A bear only sketched designs, and Chambers B and C were left bare - but its ceiling was painted with the oldest known astronomical map in Egypt, a celestial diagram divided into northern and southern sections that records the twelve months of the Egyptian civil calendar, the constellations including Meskhetyu, the Big Dipper, and the planets visible to the naked eye, with the notable exception of Mars. The ceiling has been designated a UNESCO astronomical heritage site, and it reveals Senenmut as not merely an architect but a scholar of the heavens, a man who understood that the queen's temple was aligned to the cosmos and that his own tomb should map the stars.

Then, suddenly, he disappears. The last dated inscription mentioning Senenmut is from Year 16 of Hatshepsut's reign, around 1458 BCE. After that, silence. Some scholars believe he died before the queen, his legacy destroyed during the campaign of Thutmose III to erase Hatshepsut from history and restore the male line of kings. Others suggest he fell from favour in a political purge, or that he was caught in the backlash when Hatshepsut's monuments were defaced after her death. His name was chiselled from some statues and inscriptions, though not all, and his two tombs were never used. No mummy has ever been identified as his, though some have speculated, without firm evidence, that he may be the well-preserved "Unknown Man C" from the Deir el-Bahri cache of royal mummies. The mystery of his end is as compelling as the brilliance of his career.