TP + WW = 4eva?
The formation of Towers Watson also brings together the decades of experience and history each of its predecessors brings to the table.  Towers Perrin had been in operation since 1934 as an insurance and pension advisory, although it, too, came together from earlier firms, whose history dated as far back as 1871.  Since the 1940s, Towers Perrin published its TPF&C Pension Tax Manual, which became standard issue for the Internal Revenue Service for tax law guidance.  Much of Towers' finance and insurance actuarial services were handled by its Tillinghast division, the largest practice of its kind in the world, which offered consultation and software solutions to insurance and financial services companies.

Watson Wyatt was no stranger to mergers itself; the firm was the famous product of an alliance between two longstanding actuarial legends, The Wyatt Company and R Watson & Sons.  Regarded as the world's oldest actuarial firm, R Watson & Sons began in 1878 and grew to become an industry leader largely through advisory work for the British government in establishing social insurance programs.  The Wyatt Company, meanwhile, was established as a U.S. actuarial concern in 1946 and rapidly expanded its practices and global presence through the following decades.  The two joined forces in 1995 to operate under the name Watson Wyatt Worldwide, with Wyatt Company's branches handling North American business and the R Watson & Sons group holding covering Europe.  The alliance between them was in name only, and it wasn't until 2005 that a formal merger brought them together to form a singular entity.