Hakuin Zenji (Hakuin Ekaku) 1689-1796
Hakuin is often considered the father of modern Rinzai Zen. He studied under several teachers but considered Shoju Rojin to be his dharma father. Shoju never acknowledged Hakuin's enlightenment in hopes to drive him further. Before he was able to complete his studies under Shoju he was forced to leave and run a monastery near his home and was not able to return before his teacher died.
He was considered in his time to be the greatest Rinzai Zen teacher of his age and his heritage is substaniated by the continuation of his line of Zen.
The two main extant lines of Zen extend from Hakuin
In terms of a break in the lineage we should be fully aware that Hakuin was a fully ordained and acknowleged Zen monk & priest--not just a rogue individual who established himself as a Zen Master. The lineage of Zen Buddhism rests on ordination, not on Inka-shomei or transmission by a teacher. Such transmissions do lend credibility, but these are a devise established in China. Even in the early days of Buddhism in China "transmission" was not the lineage. Lineage was a function of ordination and ordained monks then established themselves as worthy teachers. See The Ch'an & Zen Lineages Article.
For writings by Hakuin see: The Keiso dokuzi--Hakuin