First ascent.
John Watson:
It is likely children scrambled over the rocks ever since Stone Age humans carved petroglyphs in the softer caves of sandstone while they waited out storms or simply rested after hunts. They are natural challenges to anyone wishing to prove their boldness, or maybe a natural soap-box for proclaiming and rallying, or simply for viewpoints and quiet reflection. However, the first attempt at any serious climbing began in 1874 when Ernest Cézanne created the French Alpine Club in Paris. They took trains to the nearby forest of Fontainebleau, climbing some of the easier and taller pinnacles, no doubt using them to 'keep their hand in' until the summer holidays. The shadow of the Alps still loomed over the boulders until something odd happened in 1908. A small group of climbers explored the forest and formed the Groupe Rochassier which actively sought out unique short climbs in Fontainebleau that did not necessarily need ropework. Jacques Wehrlin climbed one such route in 1908 which is the large crack left of the modern classic of Duroxmanie at Cuvier East. It might not appeal to the present-day boulderer (fashions change!), but it was certainly seen as a problematic climb that required focussed technique and employed the key elements of good climbing. Wehrlin himself noted in an essay that at Fontainebleau 'the sandstone is quite smooth and the holds are rare' which suggests he was looking for something more than just the summit experience - he was after the absence of holds and the idea of impossibility, long before the likes of Philippe Le Denmat, Jacky Godoffe, Fred Nicole and other such modern luminaries.
References
[1] https://www.ukclimbing.com/articles/features/voice_in_the_forest_-_fontainebleau-1478