Janusz Korczak was the pen name of Henryk Goldszmit, born in Warsaw into a Jewish family of Polish assimilation and raised to love both literature and medicine — two vocations he spent his life pursuing simultaneously rather than choosing between. After his father's mental illness and early death left the family in financial difficulty, the young Goldszmit began writing stories, poems, and plays, and he published his first book under his pen name while still a medical student at the University of Warsaw. Walking the streets of Old Town Warsaw with friends, he encountered homeless children begging and surviving through precarious means, and this encounter permanently redirected his medical vocation: he came to believe that the only hope for humanity lay in bettering the lives of children. After graduating in medicine and completing a residency in paediatrics, he was conscripted twice to serve as a military doctor — first in the Russo-Japanese War (1905) and later in the First World War — experiences that exposed him to war's specific and devastating effects on children and deepened his resolve. Between his military obligations he built a distinguished literary reputation, developed an innovative system of child-centred orphanage administration, and conducted a regular radio programme in which he spoke directly to Polish children as a respected voice they called the Old Doctor. In 1912 he became director of Dom Sierot (the Orphan's Home) in Warsaw, a position he held for thirty years, transforming it into what he called the Children's Republic — a democratically self-governed institution whose parliament, court of peers, and children's newspaper anticipated the principles later codified in the United Nations Convention on the Rights of the Child. When the Nazis forced the residents of Dom Sierot into the Warsaw Ghetto in 1940, Korczak refused every offer of safe passage that would have separated him from his children. In the first days of August 1942, he led a procession of nearly 200 children, dressed in their best clothes and each carrying a favourite toy or book, through the streets to the Umschlagplatz, where they boarded a train for the Treblinka extermination camp. Korczak, his colleague and co-director Stefania Wilczyńska, and all the children were murdered there. He was martyred for the belief that the comfort and dignity of children were worth more than his own life.

Korczak's foundational pedagogical principle was that the child is not a future person in preparation but a person now, fully entitled to dignity, respect, and the right to be taken seriously. He argued forcefully against the pervasive adult tendency to view children as incomplete adults, as raw material to be shaped by parental and pedagogical will, insisting instead that children are already whole human beings with their own feelings, thoughts, identities, and rights. This may appear self-evident in retrospect, but in the early twentieth century it was a radical departure from both the authoritarian educational traditions of Central Europe and the sentimental idealisations of childhood that treated children as innocent objects of adult protection rather than as subjects with their own perspectives. His phrase “children are not the people of tomorrow, but people today” encapsulated a philosophy that demanded educators reorganise their practice around the actual experience and genuine agency of the child rather than around the adult's image of what the child should become.

Korczak put his philosophy into daily institutional practice through the democratic structures he created at Dom Sierot. The Children's Parliament had the authority to accept or reject proposed rules governing life in the orphanage. The Court of Peers, constituted by a jury of children, adjudicated disputes and violations — including disputes involving adults, who enjoyed no qualified immunity by virtue of their age or authority. The letterbox allowed any child to raise a question or complaint at any time, without waiting for adult permission. Rules were made by the community, and punishments — founded on the principle of forgiveness rather than retribution — were designed to help the violator understand and change their behaviour, not to humiliate or harm. Korczak's institution was, in effect, the first children's democratic republic: a proof of concept demonstrating that children, given genuine responsibility for the governance of their shared life, would rise to exercise it with seriousness, fairness, and growing civic competence. The model anticipated later developments in democratic education, participatory pedagogy, and children's rights law by decades.

Korczak dedicated his intellectual career to articulating and defending the inherent rights of children as human beings, not as concessionary privileges granted by benevolent adults. He argued that children have the right to love and respect, to be raised in conditions that allow them to grow and develop; the right to live presently as themselves, rather than be treated as future taxpayers or workers; the right to make mistakes and to fail without unjust punishment, because failure is the medium of learning; the right to be taken seriously and appreciated for their genuine capacity to communicate and contribute; the right to secret thoughts and desires; the right to their own identity, chosen by the child and not for the child; and the right to resist educational influence that contradicts their deepest beliefs. He stopped short of compiling a formal charter — his death at Treblinka deprived the world of what might have been a comprehensive declaration — but the principles scattered across his writings directly informed the 1989 United Nations Convention on the Rights of the Child, and scholars have recognised him as one of the intellectual progenitors of the international children's rights movement.

Korczak believed that the proper aim of education was not the transmission of information or the production of compliant workers but the cultivation of meaning — the development of learners who understood themselves as moral agents, capable of ethical judgment, social sensitivity, and civic participation. He argued that children must be helped to develop the capacity for self-regulation, for communicating with others, and for engaging with the social world in ways that contribute to both individual flourishing and collective wellbeing. Knowledge, in his view, had value only insofar as it contributed to a learner's ethical and personal development; education that left students more knowledgeable but no more capable of honesty, fairness, or empathy had missed its essential purpose. Against rote memorisation and passive reception he advocated hands-on, experientially grounded learning that emphasised understanding, critical inquiry, and the capacity to question accepted thought — an educational vision remarkably consonant with later progressive and constructivist traditions.

Korczak held a demanding and humbling view of the teacher's vocation. He argued that educators must dedicate their entire being to their work — not merely their technical expertise but their moral character, their emotional honesty, and their willingness to recognise and admit their own limitations. A teacher must know their strengths and weaknesses, own their mistakes, exercise self-control while giving themselves generously to students, and above all instil in students the belief in their own competence and capacity. His model of the teacher as leader-and-facilitator — someone who creates conditions for children's self-discovery rather than directing them toward predetermined destinations — anticipates modern conceptions of facilitative teaching, coaching pedagogy, and the role of self-efficacy in learning. Research conducted decades after his death has confirmed that the practices Korczak pioneered at Dom Sierot — genuine participation in decision-making, authority over community norms, and protected opportunities to fail and recover in low-stakes environments — are among the most powerful known builders of self-efficacy and intrinsic motivation.

Korczak's legacy extends into international law, child psychology, democratic education, and the abolitionist movement against corporal punishment. The UNCRC, which has been ratified by 196 countries, reflects many of his core principles, though Korczak would likely have noted — as the chapter's authors do — that the absence of enforcement mechanisms renders the declaration morally aspirational rather than legally effective, a point underscored by the World Health Organization's finding that 60% of children aged two to fourteen are regularly subjected to physical punishment by their caregivers. His insistence on the personhood and agency of children prefigured Bandura's research on self-efficacy, Bronfenbrenner's ecological systems theory, and the entire tradition of democratic and humanistic education. His children's newspaper Mały Przegląd (The Little Review), written for and by children, validated child experience as publicly significant and intellectually serious — a media experiment whose spirit lives in contemporary student journalism, youth participatory action research, and the growing recognition that children's voices are indispensable to any policy that affects their lives.

• Children of the Streets (1901)
• Child of the Drawing Room (1906)
• How to Love a Child (1919)
• King Matt the First (1923)
• When I Am Little Again (1925)
• The Child's Right to Respect (1929)
• King Matt on the Desert Island (1931)