Events January–March January 1 – (December 21, 1726 O.S.) Spain's ambassador to Great Britain demands that the British return Gibraltar after accusing Britain of violating the terms of the 1713 Treaty of Utrecht. Britain refuses and the Thirteenth Siege of Gibraltar begins on February 22. January 6 – Martin Spanberg and two other members of the First Kamchatka expedition arrive in Okhotsk, after a journey from Saint Petersburg of almost two years. After the end of winter, the 63-member group, commanded by Vitus Bering, proceeds to the Kamchatka River, to prepare for exploration of the Arctic. January 9 – The world-famous Charité Hospital is established in Berlin, to be used for research and to help the poor. Prussia's King Frederick William I had ordered the conversion of a 16-year old institution, originally built in anticipation of an epidemic of the bubonic plague. January 12 – Abd el-Sayed of Egypt is enthroned, as Pope John XVII of Alexandria becomes the leader of the Coptic Christian Church, as the 105th Pope of Alexandria and Patriarch of the Holy See of St. Mark. He will serve until his death on April 20, 1745. February - The First Saudi State is founded by Muhammad bin Saud. February 2 – Johann Sebastian Bach's solo cantata, Ich habe genug, BWV 82, premieres in Leipzig. February 20 – German composer George Frideric Handel becomes a British subject. February 22 (February 11, 1726 O.S.) – Spain besieges the British-held territory of Gibraltar, in order to recapture it. Britain's Royal Navy begins a blockade of Spanish ports and the unsuccessful siege ends with the signing of a truce on June 24. March 4 – Battle of Halidzor in Armenia: A small group of defenders overcomes a much larger Ottoman Empire army. March 9 – The west African Kingdom of Dahomey, ruled by King Trudo Agaja, conquers and annexes the Kingdom of Xwéda, after King Haffon is killed in battle (three years earlier, Agaja conquered the neighboring state of Allada). March 22 – After 55 years as Sultan of Morocco, Ismail Ibn Sharif dies at the age of 81, prompting a 30-year battle between seven of his sons, for succession to the throne. April–June April 11 – Johann Sebastian Bach's St Matthew Passion (BWV 244b) premieres at St. Thomas Church, Leipzig. May 12 – History of the Moravian Church: The 18th century renewal: The Brotherly Agreement is adopted by the