Walter the Penniless was lieutenant to Peter the Hermit and co-led the People's Crusade at the beginning of the First Crusade (1095-1099).
The Crusades were undertaken by European Christians between the 11th and 14th centuries to recover the Holy Land, particularly Jerusalem, from Islam. The movement began in France when Pope Urban II exhorted Christendom to war, promising that the journey would count as penance.
The First Crusade (1095-1099) began with the march of several undisciplined hordes of French and German peasants (approximately 12,000 people, of whom only eight were knights), led by Walter the Penniless and Peter the Hermit.
Leaving well before the main army of knights and their followers, Walter led his band, traveling separately from Peter. They started out by massacring the Jews in the Rhineland (i.e., West Germany) and incensed the Bulgarians and Hungarians, who attacked and dispersed them. They reached Constantinople in shreds. Walter and Peter joined forces at Constantinople and crossed over the Asia Minor, and were promptly defeated by the Turks.
Peter the Hermit had returned to Constantinople, either for reinforcements or to protect himself. But Walter was killed, allegedly pierced by seven arrows. Peter returned to France and joined an Augustinian monastery.
There were nine crusades, plus the Children’ Crusade of 1212. Thousands of French children set out for the Holy land but were instead sold into slavery by unscrupulous skippers. Another group of German children made their way by land but perished of hunger and disease.
Sources: Will Durant, The Age of Faith; Wikipedia; Columbia Viking Desk Encyclopedia; Webster’s Collegiate Encyclopedia.