Note that these lists might contradict with the list I compiled quite some time ago. I was confused by the fact that police province and administrative provinces use the same term "changwat" - and now it seems that the districts in that source are also police districts named "amphoe" same as the administrative ones. It's quite difficult to find the fitting announcements in the Royal Gazette, it seems the way of publishing these changes wasn't as standardized as it was since the 1950s.
Before 1915, there were 8 inner (อำเภอชั้นใน) and 8 out districts (อำเภอชั้นนอก), i.e. Phra Nakhon (พระนคร), Sampeng (สามเพ็ง), Dusit (ดุสิต), Bang Rak (บางรัก), Bangkok Noi (บางกอกน้อย), Sa Pratum Wan (สระประทุมวัน), Bangkok Yai (บางกอกใหญ่) and Banglamphu Lang (บางลำภูล่าง) as the inner; and Bang Kapi (บางกะปิ), Bang Sue (บางซื่อ), Bang Khen (บางเขน), Bang Khun Thian (บางขุนเทียน), Rat Burana (ราษฎร์บูรณะ), Taling Chan (ตลิ่งชัน), Phasi Charoen (ภาษีเจริญ), and Nong Khaem (หนองแขม) as the out district.
In 1915, the system of the inner districts was completely overhauled, as 25 new districts were created. Apparently there were no direct successors of the original districts, unlike later district creations where normally a new district is split off from a parent district. The Gazette announcements in this case however only lists the boundaries for all the 25 districts, not mentioning any of the precursor districts. The 25 districts were:
- Phra Ratcha Wang (พระราชวัง), Chana Songkhram (ชนะสงคราม), Samran Rat (สำราญราษฎร์), Phahurat (พาหุรัด) now forming the district Phra Nakhon
- Chakkrawat (จักรวรรดิ์) and Samphanthawong (สัมพันธวงษ์), now Samphanthawong
- Sam Yaek (สามแยก), merged to Samphanthawong?
- Sam Yot (สามยอด) and Pom Prap Sattru Phai (ป้อมปราบศัตรูพ่าย), now Pom Prap Sattru Phai
- Nang Liang (นางเลิ้ง) and Bang Khun Phrom (บางขุนพรหม), merged in 1929, abolished in 1938
- Sam Sen (สามเสน), merged to Dusit?
- Dusit (ดุสิต)
- Phaya Thai (พญาไท), abolished in 1929, recreated 1966
- Prachae Chin (ประแจจีน), merged into Dusit?
- Pathum Wan (ปทุมวัน)
- Bang Rak (บางรัก)
- Sathon (สาธร), abolished in 1929 and recreated in 1989
- Ban Thawai (บ้านทวาย), now Yannawa
- Bang Phlat (บางพลัด), abolished in 1938, recreated in 1989
- Amarin (อมรินทร์), now Bangkok Noi
- Hong Sa Ram (หงสาราม), now Bangkok Yai
- Ratchakhrue (ราชคฤห์), now Thon Buri
- Buppharam (บุปผาราม), now Khlong San
- Buk Lo (บุคโล), 1938 merged into Thonburi
To be continued...