Editing 1503 (section)

=== July&ndash;September ===
* [[July 23]] &ndash; Orbital calculations suggest that on this day [[Pluto]] moves outside [[Neptune]]'s orbit, remaining there for 233 years.
* [[July 30]] &ndash; [[Saint Helena]] is first definitively sighted, by ships of Portuguese navigator [[Estêvão da Gama (c. 1470)|Estêvão da Gama]] returning from the East.<ref>{{cite journal|first=A. H.|last=Schulenburg|title=The discovery of St Helena: the search continues|journal=Wirebird: The Journal of the Friends of St Helena|volume=24|date=Spring 2002|pages=13–19}}</ref><ref>{{cite book|first=Duarte|last=Leite|title=História dos Descobrimentos|volume=II|location=Lisbon|publisher=Edições Cosmos|year=1960|page=206}}</ref><ref>{{cite book|first=Fracanzio|last=da Montalboddo|title=Paesi Nuovamente Retovati & Nuovo Mondo da Alberico Vesputio Fiorentino Intitulato|location=Venice|year=1507}}</ref>
* [[August 8]] &ndash; King [[James IV of Scotland]] marries [[Margaret Tudor]], daughter of King [[Henry VII of England]], at [[Holyrood Abbey]], [[Edinburgh]], [[Scotland]].<ref>{{cite book |last1=Ring |first1=Morgan |title=So High a Blood: The Story of Margaret Douglas, the Tudor That Time Forgot |date=25 April 2017 |publisher=Bloomsbury Publishing USA |isbn=978-1-63286-607-3 |url=https://books.google.com/books?id=vIc6DgAAQBAJ&dq=%228+august+1503%22+margaret+holyrood&pg=PT18 |access-date=19 June 2023 |quote=On 8 August 1503, Margaret was led to the abbey church of Holyrood, a Gothic monastery that James had transformed into a palace. Sitting at the base of Arthur's seat, Holyrood offered Margaret new apartments, extensive gardens and respite from the noise of the city. There, she and James were married and Margaret was crowned.|language=en}}</ref>
* [[August 18]] &ndash; [[Pope Alexander VI]] dies after a reign of 11 years, and the largest gathering of cardinals up to that time— 21 from Italy, 11 from Spain and 7 from France— is called to Rome for [[September 1503 papal conclave|a papal conclave]], to start in September. 
* [[August 20]] &ndash; A previous treaty between [[Vladislaus II of Hungary]] and [[Bayezid II]], which was finalized on June 11, goes into effect.<ref>{{cite book |last1=Pálosfalvi |first1=Tamás |title=From Nicopolis to Mohács: A History of Ottoman-Hungarian Warfare, 1389-1526 |date=20 September 2018 |page=321|publisher=Brill |isbn=978-90-04-37565-9 |url=https://brill.com/display/title/37925?language=en |access-date=19 June 2023 |language=en}}</ref> The treaty suppresses warfare along the Hungarian-Ottoman border. [[Stephen III of Moldavia]] is also included in this treaty, but it preserves his nation's independence on the condition Moldavia pays an annual tribute to the [[Ottoman Empire]].
* [[September 22]] &ndash; Francesco Todeschini Piccolomini, Archbishop of Siena, is elected as the new Pope after the voting cardinals cannot decide between Georges d'Amboise of France or Giuliano della Rovere of Italy. Piccolomini takes the name of [[Pope Pius III]] but will reign for only 26 days.<ref>{{cite book |last1=Frieda|first1=Leonie|title=The deadly sisterhood : a story of women, power and intrigue in the Italian Renaissance, 1427-1527|date=2013|publisher=Phoenix|location=London|isbn=978-0-7538-2844-1|edition=Paperback |pages=275–276}}</ref>