Chiara Lubich, mystic, bestselling author and spiritual leader, was the founder and president of the Focolare movement, an international network modelled on small communities whose members, whether married or single, were devoted to the ideal of unity between all nations, religions and races. Under her leadership, Focolare spread to more than 180 countries, and had 140,000 members as well as 2.1 million affiliates, including Roman Catholic, Protestant and Orthodox believers as well as members of other faiths.

Deeply influenced by the ravages of the Second World War, Focolare was one of the so-called “new Catholic movements” that blossomed and reinvigorated the Church during the pontificate of John Paul II and continued under Benedict XVI. But the road to official recognition had been long and, at times, hard.

Born in 1920 in the northern Italian city of Trento, Lubich was baptised Silvia but changed it to Chiara (Clare) on joining the Franciscan Third Order in her teens. She was brought up with the traditional Catholic piety of her mother but was equally strongly influenced by her father's socialist and anti-fascist views.

Chiara Lubich was a 24-year-old primary school teacher when she launched her movement with a group of young women, some of them former pupils, in her native Trento in 1944. Despite its homespun name - focolare means hearth - the fledgeling organisation had a revolutionary impact on the stagnating Catholicism of its time. Many of its innovations - a reassessment of the importance of the laity, a return to scripture, a joyful liturgy using popular tunes of the day, an emphasis on the key gospel message of love and unity - anticipated the direction that the Second Vatican Council would take 20 years later.

In the final years of the Second World War, Trento, still under German occupation, endured heavy Allied bombing. With death staring them in the face, Lubich and her disciples felt the urgency of penetrating to the heart of the Christian message by closely studying the gospels. By candle-light in a makeshift air-raid shelter, they discovered the biblical phrase that was to be their inspiration for the next 60 years: “That all may be one” (John xvii, 21). Unity, achieved through mutual love, became the watchword of the group from that day on. Not surprisingly, the practice of reading the New Testament drew accusations of Protestantism and the predilection for the word “unity” aroused suspicions of communism.

Early followers were amazed that the movement could achieve unity between members from Trento and the nearby city of Bolzano: this was an improbable achievement in a country famous for its campanilismo (local chauvinism). But already Lubich had set her sights on a far more ambitious goal. For her, “That all may be one” could mean nothing less than the unity of all mankind. It was this vision and single-mindedness that propelled the astonishing growth of the nascent community. By the end of the 1940s Focolare had spread throughout Italy; in the next decade it fanned out across Europe and by the end of the 1960s it had reached every continent. But Lubich never saw her movement as of a purely religious nature. As early as 1948, when she moved the Focolare headquarters to Rome, she visited the Italian parliament where she met Igino Giordani, a founding member of the Christian Democrat Party. Giordani, who had a lifelong fascination with St Catherine of Siena, saw in this young provincial woman a 20th-century Catherine, whose ideas would influence not only the Church but also the political and social fields. Then in his fifties, the veteran politician became Lubich's most devoted follower and was regarded by her as a co-founder of the movement.

The Italian Prime Minister Alcide De Gasperi, another Trentino and one of the founding fathers of the European Union, was also impressed, becoming a disciple. Much later this aspect of Lubich's activities resulted in a new school of economics - the Economy of Communion, which applied the movement's practice of sharing material goods to business enterprises - and the International Political Movement for Unity, which encouraged cross-party collaboration and drew such political luminaries as Romano Prodi, who collaborated with Lubich on a number of projects.

After a gruelling examination by the pre-conciliar Holy Office, much of it directed at Lubich herself by the notoriously conservative Cardinal Ottaviani, Focolare was granted official Vatican approval in the mid-1960s. In this period Lubich was founding new branches for priests, religious, seminarians, young people, professionals, families - even toddlers had their own special section. She had begun to establish model towns intended to serve as laboratories for the reconstruction of society - today there are 20 of them around the globe, although the founder envisaged there should eventually be a thousand.

As early as the 1950s Lubich enthusiastically took up the cause of ecumenism, then almost unthinkable in Catholic circles. Relations with German Lutherans began in 1959, while in the early 1960s the first contacts were established with Anglicans in the UK. The close personal rapport between Lubich and Patriarch Athenagoras of Constantinople led to Lubich acting as something of an emissary between the Orthodox leader and Pope Paul VI.

Later she became involved in multi-faith dialogue and in 1994 was appointed an honorary president of the World Conference for Religion and Peace.

She was the first Christian and the first woman to preach in the Malcolm X Mosque in Harlem, New York, where in May 1997 she addressed 3,000 African-American Muslims. By special permission of the Vatican, Focolare was the first Catholic organisation to admit members of other Christian churches and other faiths to its communities.

In her late eighties Lubich's activities, particularly outside the movement, actually increased and she received numerous civic awards and honorary degrees. To mark her 80th birthday in January 2000, in an extraordinary letter of homage Pope John Paul II, who had made a practice of calling her personally each year on the feast of Saint Clare, hailed her as “a messenger of unity and mercy among many brothers and sisters in every corner of the world”.

Her religious awards included the Templeton Prize for Religion presented by the Duke of Edinburgh at Guildhall in 1977 and the Order of St Augustine, which she received from Archbishops Runcie and Carey.

Although in the 1940s and 1950s her movement had been in the vanguard of Catholicism, by the end of the 1990s, it was doctrinally firmly in the Church's conservative camp - a trajectory not unlike that of Opus Dei, an organisation that in many ways it resembles.

In spite of her innovations, her work for ecumenism and interfaith understanding, Lubich was at heart a traditionalist, inspired as much by Catholicism's illustrious past as the possibilities for its future. John Paul II chose his words advisedly when he hailed her as “a great Catholic”.

Chiara Lubich, founder of the Focolare movement, was born on January 22, 1920. She died on March 14, 2008, aged 88