DOLLIER DE CASSON, Francis, clergyman, born in France about 1630; died in Canada. The Sulpitians, being anxious to compete with the Jesuits in missionary enterprise, sent Father Dollier de Casson to winter with the Nipissings in 1668. In company with Lasalle and twenty-one other Frenchmen, he set out for the Seneca country, being guided by some Senecas, and at Tenaoutona met Jollier, and received from him information as to the west, which enabled them to draw a map. But here Lasalle and his party refused to proceed farther. They returned to the St. Lawrence, and, as they had boasted that they were going to China, the name of Lachine was given to Lasalle's place in ridicule. Dollier de Casson, with the nine that remained faithful, set out from Tenaoutona in October 1669, reached Lake Erie, and spent the winter near the mouth of Grand River on the north shore, and in March 1670, drew up an act of possession. They then continued their voyage, but had to abandon their project, owing to a storm, and made for the Jesuit mission of Sault St. Marie, which they reached in May. Father Dollier de Casson was the first to sail through Lake Erie and Lake St. Clair. He was the author of a "History of Montreal."