The remarkable archive was formed by two prominent naval historians, Oscar Parkes and Wilfrid Pym Trotter. Both collections have been held in a trust, and are now appearing at auction for the first time.
After entering the Navy, Dr Oscar Parkes served with the Naval Intelligence Division at the Admiralty. He later worked as editor of Jane's Fighting Ships from 1918 to 1935 and contributed to many naval journals. He was the author of several books and also a very capable marine artist, exhibiting at the Royal Academy.
Wilfrid Pym Trotter joined the Royal Fusiliers in 1915 and was awarded a Military Cross for his part in a successful raid on German trenches in the Ypres Salient in 1917. Later that same year he was awarded a bar to his MC after the bitter fighting at Menin Road.
After retirement from the army, Trotter worked in banking and concentrated on developing his vast collection related to British naval vessels, having his own rooms at the Imperial War Museum which housed his collection, and where curators could seek his advice.
The archive has been divided into over 350 lots and includes all manner of craft: there are postcards of Dutch naval vessels, oil tankers, tugs, Royal yachts, motor launches, coastal destroyers, whalers, submarines, paddle steamers, minesweepers, lifeboats, barges, trawlers and landing craft.
Lawrences' Simon Jones said: "This is an amazingly extensive collection and an absolute must for naval enthusiasts. The sheer quantity of items and information contained in this collection is quite remarkable and it should attract a huge amount of interest from collectors and institutions."
Estimates have been set to attract private collectors and begin at just £40 for a lot of 50 postcards with 30 photographs. The collection will be offered on May 5 as part of a two-day militaria and collectors' sale.