Background: Bertrand Arthur William Russell, 3rd Earl Russell,  (; 18 May 1872 - 2 February 1970) was a British philosopher, logician, mathematician, historian, writer, social critic, political activist and Nobel laureate. At various points in his life, Russell considered himself a liberal, a socialist and a pacifist, but he also admitted that he had "never been any of these things, in any profound sense". Russell was born in Monmouthshire into one of the most prominent aristocratic families in the United Kingdom. In the early 20th century, Russell led the British "revolt against idealism".
Context: Russell had two siblings: brother Frank (nearly seven years older than Bertrand), and sister Rachel (four years older). In June 1874 Russell's mother died of diphtheria, followed shortly by Rachel's death. In January 1876, his father died of bronchitis following a long period of depression. Frank and Bertrand were placed in the care of their staunchly Victorian paternal grandparents, who lived at Pembroke Lodge in Richmond Park. His grandfather, former Prime Minister Earl Russell, died in 1878, and was remembered by Russell as a kindly old man in a wheelchair. His grandmother, the Countess Russell (nee Lady Frances Elliot), was the dominant family figure for the rest of Russell's childhood and youth. The countess was from a Scottish Presbyterian family, and successfully petitioned the Court of Chancery to set aside a provision in Amberley's will requiring the children to be raised as agnostics. Despite her religious conservatism, she held progressive views in other areas (accepting Darwinism and supporting Irish Home Rule), and her influence on Bertrand Russell's outlook on social justice and standing up for principle remained with him throughout his life. (One could challenge the view that Bertrand stood up for his principles, based on his own well-known quotation: "I would never die for my beliefs because I might be wrong".) Her favourite Bible verse, 'Thou shalt not follow a multitude to do evil' (Exodus 23:2), became his motto. The atmosphere at Pembroke Lodge was one of frequent prayer, emotional repression, and formality; Frank reacted to this with open rebellion, but the young Bertrand learned to hide his feelings. Russell's adolescence was very lonely, and he often contemplated suicide. He remarked in his autobiography that his keenest interests were in religion and mathematics, and that only his wish to know more mathematics kept him from suicide. He was educated at home by a series of tutors. When Russell was eleven years old, his brother Frank introduced him to the work of Euclid, which transformed his life. During these formative years he also discovered the works of Percy Bysshe Shelley. In his autobiography, he writes: "I spent all my spare time reading him, and learning him by heart, knowing no one to whom I could speak of what I thought or felt, I used to reflect how wonderful it would have been to know Shelley, and to wonder whether I should meet any live human being with whom I should feel so much sympathy". Russell claimed that beginning at age 15, he spent considerable time thinking about the validity of Christian religious dogma, which he found very unconvincing. At this age, he came to the conclusion that there is no free will and, two years later, that there is no life after death. Finally, at the age of 18, after reading Mill's "Autobiography", he abandoned the "First Cause" argument and became an atheist. Russell won a scholarship to read for the Mathematical Tripos at Trinity College, Cambridge, and commenced his studies there in 1890, taking as coach Robert Rumsey Webb. He became acquainted with the younger George Edward Moore and came under the influence of Alfred North Whitehead, who recommended him to the Cambridge Apostles. He quickly distinguished himself in mathematics and philosophy, graduating as seventh Wrangler in the former in 1893 and becoming a Fellow in the latter in 1895. Russell first met the American Quaker Alys Pearsall Smith when he was 17 years old. He became a friend of the Pearsall Smith family - they knew him primarily as "Lord John's grandson" and enjoyed showing him off. He traveled with them to the continent; it was in their company that Russell visited the Paris Exhibition of 1889 and was able to climb the Eiffel Tower soon after it was completed. He soon fell in love with the puritanical, high-minded Alys, who was a graduate of Bryn Mawr College near Philadelphia, and, contrary to his grandmother's wishes, married her on 13 December 1894. Their marriage began to fall apart in 1901 when it occurred to Russell, while he was cycling, that he no longer loved her. She asked him if he loved her and he replied that he did not. Russell also disliked Alys's mother, finding her controlling and cruel. It was to be a hollow shell of a marriage and they finally divorced in 1921, after a lengthy period of separation. During this period, Russell had passionate (and often simultaneous) affairs with a number of women, including Lady Ottoline Morrell and the actress Lady Constance Malleson. Some have suggested that at this point he had an affair with Vivienne Haigh-Wood, the English governess and writer, and first wife of T. S. Eliot. Russell began his published work in 1896 with German Social Democracy, a study in politics that was an early indication of a lifelong interest in political and social theory. In 1896 he taught German social democracy at the London School of Economics. He was a member of the Coefficients dining club of social reformers set up in 1902 by the Fabian campaigners Sidney and Beatrice Webb. He now started an intensive study of the foundations of mathematics at Trinity. In 1898 he wrote An Essay on the Foundations of Geometry which discussed the Cayley-Klein metrics used for non-Euclidean geometry. He attended the International Congress of Philosophy in Paris in 1900 where he met Giuseppe Peano and Alessandro Padoa. The Italians had responded to Georg Cantor, making a science of set theory; they gave Russell their literature including the Formulario mathematico. Russell was impressed by the precision of Peano's arguments at the Congress, read the literature upon returning to England, and came upon Russell's paradox. In 1903 he published The Principles of Mathematics, a work on foundations of mathematics. It advanced a thesis of logicism, that mathematics and logic are one and the same. At the age of 29, in February 1901, Russell underwent what he called a "sort of mystic illumination", after witnessing Whitehead's wife's acute suffering in an angina attack. "I found myself filled with semi-mystical feelings about beauty ... and with a desire almost as profound as that of the Buddha to find some philosophy which should make human life endurable", Russell would later recall. "At the end of those five minutes, I had become a completely different person." In 1905 he wrote the essay "On Denoting", which was published in the philosophical journal Mind. Russell was elected a Fellow of the Royal Society (FRS) in 1908. The three-volume Principia Mathematica, written with Whitehead, was published between 1910 and 1913. This, along with the earlier The Principles of Mathematics, soon made Russell world-famous in his field. In 1910 he became a University of Cambridge lecturer at Trinity College where he studied. He was considered for a Fellowship, which would give him a vote in the college government and protect him from being fired for his opinions, but was passed over because he was "anti-clerical", essentially because he was agnostic. He was approached by the Austrian engineering student Ludwig Wittgenstein, who became his PhD student. Russell viewed Wittgenstein as a genius and a successor who would continue his work on logic. He spent hours dealing with Wittgenstein's various phobias and his frequent bouts of despair. This was often a drain on Russell's energy, but Russell continued to be fascinated by him and encouraged his academic development, including the publication of Wittgenstein's Tractatus Logico-Philosophicus in 1922. Russell delivered his lectures on Logical Atomism, his version of these ideas, in 1918, before the end of World War I. Wittgenstein was, at that time, serving in the Austrian Army and subsequently spent nine months in an Italian prisoner of war camp at the end of the conflict. CANNOTANSWER
Question: What lead up to his early carrer?

Answer:

When Russell was eleven years old, his brother Frank introduced him to the work of Euclid, which transformed his life.