Who was the first person to fly above 20,000 feet, and what aircraft was used?

Question

Oh! I have slipped the surly bonds of Earth
And danced the skies on laughter-silvered wings;
Sunward I’ve climbed, and joined the tumbling mirth
of sun-split clouds, — and done a hundred things
You have not dreamed of – wheeled and soared and swung
High in the sunlit silence. Hov’ring there,
I’ve chased the shouting wind along, and flung
My eager craft through footless halls of air....

Up, up the long, delirious, burning blue
I’ve topped the wind-swept heights with easy grace.
Where never lark, or even eagle flew —
And, while with silent, lifting mind I've trod
The high untrespassed sanctity of space,
– Put out my hand, and touched the face of God.

("High Flight" by John Gillespie Magee Jr.)

From what I've seen, it seems that eagles can fly up to about 20,000 feet. Who was the first human aviator to reach this altitude in sustained flight, and what aircraft was used?

If the initial record was not set on an aircraft with wings, I would also be interested in the first time it was done in a fixed-wing aircraft, because while a balloon pilot may have "slipped the surly bonds of Earth," they have not "danced the skies on laughter-silvered wings."

Answer 1

According to Wikipedia in a balloon:

1803-07-18: 7.28 km (23,900 ft); Étienne-Gaspard Robert and Auguste Lhoëst in a balloon.

and fixed wing:

1916 November 9 26,083 ft 7,950 m Guido Guidi Caudron G.4 propeller Torino Mirafiori airfield

Answer 2

Étienne Gaspard Robert (sometimes Robertson), a Belgian stage magician, certainly claimed to have reached 7,171 metres (23,526 feet) in July 1803, which is the record stated by Wikipedia. This was in the balloon L'Entrepement which had first flown in 1794, and had been used in the Napoleonic wars.

There is some doubt as to his claim, in particular scepticism that such a small balloon could reach that altitude carrying two people, and his "outlandish description of the effects of the high altitude".

L'Entreprenant used by the French Republican Army to observe the combined Austrian and Dutch army at Maubeuge on 26 June 1794. This became the first battle to be won through control of the air.

A more authoritative experiment took place a year later:

The scientists J.B. Biot and Joseph Louis Gay-Lussac made electromagnetic observations in their flight from the Conservatoire des Arts et Métiers in Paris on August 24, 1804. According to their barometer, they rose to 13,000 feet (3,962 meters).

Later, Gay-Lussac made another flight by himself and ascended to 23,000 feet (7,010 meters) — a record that was held for 50 years. At that height, he experienced quickened pulse, shortness of breath, and finally unconsciousness—symptoms of oxygen deprivation — until the balloon began to descend. He still managed, however, to collect air samples at over 20,000 feet (6,000 meters), study the variation of pressure and temperature, and repeat his earlier electromagnetic observations.

source

So we can't really be sure who was the first aviator, though I'm more inclined to accept 1804. It's also worth mentioning that the Incas had ascended mountains higher than 20,000 feet by the fifteenth century.