Question: Rigid frame airships were used by Germany to fly bombing raid over Great Britian in what war?

<P0-S0> Airship development in the United Kingdom lagged behind that of Germany and France. <P0-S1>  The first British designed and built airship was constructed by Stanley Spencer, and on 22 September 1902 was flown 30 mi from Crystal Palace, London to Ruislip, carrying an advertisement for baby food. <P0-S2>  A series of more practical airships was constructed by Ernest Willows, the "Willows Number 1" making its first flight near Cardiff on 5 August 1905. <P0-S3>  The Royal Navy realised that airships similar to Ferdinand von Zeppelin's designs could be of great use and in 1909 ordered construction of a rigid airship. <P0-S4>  This was completed in 1911 but was wrecked while leaving the hangar before it had flown. <P0-S5>  Meanwhile, the British Army's School of Ballooning, later the Air Battalion Royal Engineers, acquired a small fleet of semi-rigid and non-rigid airships for observation purposes; they were taken over by the Royal Navy on the creation of the Royal Naval Air Service in 1914. <P0-S6>  A large number of rigid and non-rigid airships were mainly used to counter the U-Boat campaign in World War I. <P0-S7>  Interest in military airships declined at the end of the war, but some success in the commercial field inspired the Imperial Airship Scheme; however, the disastrous crash of the R101 in 1930 ended serious government and commercial interest in airships. <P0-S8>  Since the 1970s, there have been persistent efforts to revive a British airship industry, using new designs, materials and technologies. <SEP> <P1-S0> The best-known German strategic bombing campaign during World War I was the campaign against England, although strategic bombing raids were carried out or attempted on other fronts. <P1-S1>  The main campaign against England started in January 1915 using airships. <P1-S2>  From then until the end of World War I the German Navy and Army Luftstreitkräfte mounted over 50 bombing raids on the United Kingdom. <P1-S3>  These were generally referred to as "Zeppelin raids": although both Zeppelin and Schütte-Lanz airships were used, the Zeppelin company was much better known and was responsible for producing the majority of the airships used. <P1-S4>  Weather conditions and night flying conditions made airship navigation and maintaining bombing accuracy difficult. <P1-S5>  Bombs were often dropped miles off target (one raid on London actually bombed Hull) and accurate targeting of military installations was impossible. <P1-S6>  The civilian casualties made the Zeppelins an object of hatred, and they were dubbed "baby-killers". <P1-S7>  With the development of effective defensive measures the airship raids became increasingly hazardous, and in 1917 the airships were largely replaced by aeroplanes. <SEP> <P2-S0> Peter Strasser (1 April 1876 – 5 August 1918) was chief commander of German Imperial Navy Zeppelins during World War I, the main force operating bombing campaigns from 1915 to 1917. <P2-S1>  He was killed when flying the war's last airship raid over Great Britain. <SEP> <P3-S0>  Zeppelin's notions were first formulated in 1874 and developed in detail in 1893. <P3-S1>  They were patented in Germany in 1895 and in the United States in 1899. <P3-S2>  After the outstanding success of the Zeppelin design, the word "zeppelin" came to be commonly used to refer to all rigid airships. <P3-S3>  Zeppelins were first flown commercially in 1910 by Deutsche Luftschiffahrts-AG (DELAG), the world's first airline in revenue service. <P3-S4>  By mid-1914, DELAG had carried over 10,000 fare-paying passengers on over 1,500 flights. <P3-S5>  During World War I the German military made extensive use of Zeppelins as bombers and scouts, killing over 500 people in bombing raids in Britain. <P3-S6> A Zeppelin was a type of rigid airship named after the German Count Ferdinand von Zeppelin (] ) who pioneered rigid airship development at the beginning of the 20th century.