Edgar Semmens was married to Anna Siebenhaar, who had arrived from the Netherlands in the 1890s, following her younger brother the socialist and activist Willem Siebenhaar who had arrived in Perth a few years earlier.

Source: Sunday Times Perth
 Sun 3 May 1925  (Trove)

As a result of his marriage to Anna – who was active in the small Dutch community in Perth, Edgar became one of the founding member of the WA branch of the Netherlands Chamber of Commerce for Australasia which had been established in Melbourne in 1903, and he developed a strong interest in trade and commerce, which he pursued in his spare time from his civil service job (in 1908, he was promoted to Deputy District Registrar for Perth).

In 1910, when his long service leave became due, Edgar was granted 12 months leave on half pay from his position to travel to Europe with the aim of promoting improved trade links between WA and the and the Netherlands East Indies (NEI). Semmens pointed out that for 1909, WA imported £54,773 worth of goods from Java and £26,480 from the Netherlands, whilst the State only exported £2,480 worth of goods to Java and nothing to the Netherlands. Although he was undertaking the trip in an independent capacity, Semmens was provided with a letter of introduction to the Dutch Government from the State Premier and he was permitted to give papers in Den Haag, Amsterdam and Rotterdam.

In 1911, it was reported that there were many enquiries about WA from potential emigrants in the Netherlands, and the State Government had even appointed an emigration agent there, although this appointment did not fulfil expectations. However, the enquiries had not led to many new arrivals, with the 1911 census recording a Netherlands born population in WA of only eighty-four, out of a total State population of 282,114 (0.03%). Australia-wide in 1911, there were only 745 Netherlands born of a total population of 4,455,005 (0.017%)75. The figures for State financially assisted immigration into WA from overseas for the year ended 30 June 1912 were 9,697 passages in total, of which all came from the British Isles except forty-eight from various European countries, of whom nearly all had been nominated by their friends already in the State. Only one of these forty-eight was from Holland. The official immigration statistics for the period 1901 to 1915 show net Dutch arrivals in WA of only 117 (218 arrivals minus 101 departures), and this included forty sailors from the Royal Dutch Navy who ‘arrived’ as deserters at Fremantle in 1910. Edgar was on a mission to do something about improving the trade deficit and the poor immigration performance of WA with the Netherlands and its colonies in the East Indies. He and Anna sailed for the NL in May 1911. Edgar was able to meet with the Dutch Minister for Commerce regarding WA matters and gave various lectures.

Edgar and Anna returned from Europe in April 1912 and Edgar presented the State Government with a report on his findings regarding trade opportunities with the Netherlands and the East Indies, which was published in The West Australian’. Edgar Semmens continued to promote trade between the two countries and wrote many articles that were published in the local papers and even in the British Trade Journal into the 1920

Anna and Edgar divorced, Edgar Semmens was promoted to District Registrar for Perth in 1925 and remarried Ivy Cooper at Perth in 1938. He died in 1958 at Mt Hawthorn, WA.

This is an abstract from an article in the book ‘A Touch of Dutch’ by Neil Foley