Sir Herbert Robin Cayzer, 1st Baronet of Tylney and Baron Rotherwick (1881–1958) was the fifth son of Sir Charles Cayzer, 1st Baronet, and arguably the most dynamic of his children.

After completing his education at Rugby in 1899, Herbert joined the Glasgow office of Cayzer, Irvine & Company, where he learned the business from the ground up. He shared a flat with his elder brother August, with whom he not only worked closely but also engaged in various extracurricular pursuits. Herbert’s extroverted personality and strong interpersonal skills propelled him to success—not only in the family business but also as a Member of Parliament and as a soldier during the First World War, where he was mentioned in dispatches for his service.

Following his father's death in 1916, Herbert became Vice-Chairman of the Company, supporting August, who had taken over as Chairman. In the 1918 “Khaki Election,” he was elected Conservative MP for Portsmouth South, becoming a popular local figure. He was instrumental in repurposing the former Naval dockyard to refit the company's fleet, providing employment for hundreds. In Parliament, he became a forceful advocate for British shipping and was appointed chairman of the newly formed Shipping Committee in 1932. He had previously been awarded a baronetcy in 1924 by Stanley Baldwin for his political contributions, and in 1939 was elevated to the peerage as the 1st Baron Rotherwick in recognition of his services to the shipping industry.

During the Second World War, he was appointed President of the United Kingdom Chamber of Shipping. In this role, he strongly championed the protection of merchant shipping, declaring it “our lifeline,” without which “the fighting services will be unable to function and our civil population will starve.”

Herbert became Chairman of the Company in 1943 upon August’s death. Under his leadership, the company underwent a significant transformation. He foresaw the impact of air travel on traditional shipping and, in 1956, oversaw the merger of the Clan Line Steamers and Union-Castle Mail Steamship Company, forming British & Commonwealth Shipping.

Upon his death in 1958, his nephew Nicholas succeeded him as Chairman.