The short answer is: in Amsterdam, Paris and New York. Below is lots of other info.

Piet Mondrian was a 20th century abstract painter whose most famous compositions are made up of black lines and colored rectangles. Mondrian's early works were naturalistic and impressionistic landscapes, but his discovery of cubism around 1910 put him on the path toward abstraction. He left home in the Netherlands for Paris in 1912, but returned to the Netherlands in 1914 to take care of his sick father. He remained there during World War I, tryIng out abstract forms and experImentIng wIth a technIc he called neo-plasticism. He went back to Paris after the war, he made what may be his most famous painting, "Composition with Red, Yellow and Blue" In 1921, a composition of primary colors in rectangles on a grid of black lines. In 1938 he traveled to England and in 1940 he moved to New York, where he continued to take away "non-essentials" and restrict his works to "basic forms of beauty." Influenced by the philosophical approach of theosophy, Mondrian believed painting to be a two-dimensional interpretation of nature that is guided by the artist's intuition. His paintings include "Still Life with Ginger Pot I" paInted In1911, "Composition" In 1916) and "Broadway Boogie Woogie" paInted through1942-43.

He died of pneumonia.

[As he died on 1 February, 1944 - it would be jokingly said in Dublin that "he died of a Tuesday".]

3-letter words

ado, aid, aim, ain, air, ait, ami, amp, and, ane, ani, ant, ape, apt, are, arm, art, ate, dam, dap, dei, den, die, dim, din, dip, dit, doe, dom, don, dor, dot, ear, eat, end, eon, era, ern, eta, imp, inn, ion, ire, mad, mae, man, map, mar, mat, med, men, met, mid, mir, moa, mod, mon, mop, mor, mot, nae, nam, nap, net, nim, nip, nit, nod, nom, nor, not, oar, oat, ode, one, ope, opt, ora, ore, ort, pad, pam, pan, par, pat, pea, ped, pen, per, pet, pia, pie, pin, pit, pod, poi, pot, pro, rad, ram, ran, rap, rat, red, rei, rem, rep, ret, ria, rid, rim, rin, rip, rod, roe, rom, rot, tad, tae, tam, tan, tao, tap, tar, tea, ted, ten, tie, tin, tip, tod, toe, tom, ton, top, tor

4-letter words

adit, aeon, aero, aide, airn, airt, amen, amid, amie, amin, amir, anon, ante, anti, aped, aper, apod, arid, atom, atop, dame, damn, damp, dare, darn, dart, date, dato, dean, dear, demo, dent, derm, diet, dime, dine, dint, dipt, dire, dirt, dita, dite, doat, doer, doit, dome, dona, done, dopa, dope, dore, dorm, dorp, dote, dram, drat, drip, drop, earn, edit, emir, emit, etna, idea, idem, imid, impi, inia, inro, inti, into, iota, ired, irid, iron, item, made, maid, main, mair, mane, mano, mare, mart, mate, mead, mean, meat, mend, meno, meta, midi, mien, mina, mind, mine, mini, mint, mire, miri, mite, moan, moat, mode, modi, mope, mora, more, morn, mort, mote, name, naoi, nape, nard, neap, near, neat, nema, neon, nerd, nide, nidi, nine, nipa, node, nodi, noma, nome, nona, none, nope, norm, nota, note, odea, omen, omer, omit, oped, open, orad, padi, paid, pain, pair, pane, pant, pard, pare, part, pate, pean, pear, peat, pein, pend, pent, peon, peri, perm, pert, pian, pied, pier, pima, pina, pine, pint, pion, pirn, pita, poem, poet, pome, pond, pone, pore, porn, port, pram, prao, prat, prim, proa, prod, prom, raid, rain, rami, ramp, rand, rani, rant, rape, rapt, rate, rato, read, ream, reap, redo, rein, rend, rent, repo, ride, rime, rind, riot, ripe, rite, road, roam, roan, rode, romp, rope, rota, rote, tain, tame, tamp, tape, tare, tarn, taro, tarp, team, tear, temp, tend, tepa, term, tern, tide, tied, tier, time, tine, tipi, tire, tiro, toad, toea, toed, tome, tone, tope, topi, tora, tore, tori, torn, trad, tram, trap, trim, trio, trip, trod, trop

5-letter words

adept, admen, admit, adopt, adore, adorn, aider, aimed, aimer, aired, amend, ament, amide, amido, amine, amino, amort, anent, anime, animi, anion, anode, anted, antre, aport, apron, apter, armed, armet, aroid, arpen, atone, atrip, danio, dater, deair, demit, demon, denim, depot, derat, derma, dimer, dinar, diner, donna, donne, doper, doter, drain, drape, dream, dript, droit, drone, dropt, enorm, entia, idiom, idiot, imide, imido, imine, imino, imped, inane, inapt, inarm, indie, indri, inept, inert, inion, inned, inner, inter, intro, iodin, irade, irate, irone, madre, maned, manor, mated, mater, matin, meant, media, medii, menad, menta, merit, metro, minae, mined, miner, minor, mired, miter, mitre, moira, moire, monad, monde, monie, monte, moped, moper, morae, nadir, named, namer, netop, niter, nitid, niton, nitre, nitro, nomad, nomen, nonet, noria, noted, noter, oared, oaten, oater, oidia, opera, opine, opted, orate, oread, orpin, padre, padri, paeon, paint, paned, panne, panto, pardi, pared, pated, paten, pater, patin, patio, peart, pedro, penna, penni, piano, pieta, pined, pinna, pinon, pinot, pinta, pinto, piton, podia, poind, point, pored, prate, pride, pried, prima, prime, primi, primo, print, proem, prone, radii, radio, radon, ramet, ramie, ranid, raped, rapid, rated, ratio, redan, redia, redip, redon, reman, remap, remit, renin, repin, repot, retia, riant, rimed, riped, ripen, roman, roped, tamed, tamer, taped, taper, tapir, tardo, tared, teiid, teind, tempi, tempo, tenia, tenon, tenor, tepid, terai, timed, timer, timid, tinea, tined, tired, toman, tondi, toned, toner, tonne, toped, toper, torii, trade, train, tramp, tread, trend, triad, tried, trine, tripe, trode, tromp, trona, trone, trope

6-letter words

admire, adroit, aidmen, airmen, airted, amidin, amnion, anoint, anomie, ardent, armpit, aroint, arpent, atoned, atoner, daemon, daimen, daimio, daimon, damner, dampen, damper, dentin, depart, deport, detain, diamin, diaper, diapir, diatom, dinero, dinner, domain, domine, donate, dopant, dopier, dormie, dormin, dotier, dreamt, editor, emodin, enamor, endrin, enrapt, entrap, eonian, etamin, imaret, impair, impart, impend, impone, import, inaner, indent, indite, inmate, innate, inroad, intend, intern, intima, intime, intine, intone, intron, iodate, iodine, ironed, maiden, manito, manned, manner, mantid, marine, marted, marten, martin, matron, median, medina, mentor, merino, midair, minder, minion, minted, minter, mitier, mitred, moaned, moated, modern, moirai, monied, mopier, narine, nation, natron, nimrod, nitrid, nomina, nonart, nonpar, norite, normed, omenta, opiate, opined, optima, optime, orated, ordain, orient, ornate, orpine, pained, paired, pander, pandit, panier, panned, panted, pantie, pardie, pardon, parent, parted, parton, patine, patron, pedant, penman, pennia, pentad, period, permit, petard, pinder, pineta, pinier, pinion, pinite, pinnae, pinned, pinner, pirate, pitied, pitier, pitman, pitmen, podite, pointe, pomade, ponder, ponent, ponied, ported, potman, potmen, prated, preman, primed, protea, protei, pterin, radome, rained, ramped, random, ranted, rapine, ratine, ration, redipt, redtop, remain, remand, remind, remint, repaid, repand, retain, retina, rident, rioted, roadie, roamed, rodent, rodman, rodmen, romped, tamein, tamped, tamper, tampon, tandem, tanned, tanner, tarpon, tendon, tenpin, teopan, tidier, tiepin, tinder, tineid, tinier, tinman, tinmen, tinned, tinner, tirade, tonier, tonner, torpid, trepan, trepid, trined, triode, tripod, trompe, tropin

7-letter words

adopter, airtime, amidine, amidone, amniote, amorini, andiron, aneroid, antired, aproned, atropin, denarii, depaint, detrain, diamine, diatron, diopter, dioptre, diorite, dipnoan, diptera, dominie, donnert, dormant, edition, emporia, enation, entrain, epinaoi, impaint, imperia, imponed, imprint, inarmed, indamin, inditer, inedita, inertia, interim, intimae, intoned, intoner, madrone, maintop, mannite, manrope, martini, mediant, mention, meropia, midiron, minaret, minored, mintier, montane, moraine, mordant, mordent, nardine, nitride, nonmeat, notepad, operand, operant, opiated, padrone, padroni, painted, painter, pandore, pannier, pardine, parotid, partied, patined, pendant, peridia, peridot, pertain, pimento, pinnate, pintado, pintano, pirated, pointed, pointer, poniard, pontine, portend, primate, primine, printed, promine, pronate, protean, proteid, protein, protend, ptomain, raiment, rampion, readmit, readopt, remnant, repaint, ripieno, riptide, romaine, tampion, termini, ternion, tiderip, timider, timpani, timpano, tinnier, tonearm, trained, tramped, tromped, tropine

8-letter words

anointed, anointer, antinode, antipode, arointed, atropine, daintier, demonian, dipteran, dipteron, diriment, dominant, dominate, dopamine, dormient, endpoint, ideation, impaired, imparted, imported, indamine, indentor, intrepid, iodinate, mediator, meridian, midpoint, nominate, nonrated, ordinate, ornament, orpiment, paintier, piedmont, pimiento, pinioned, pinnated, pointier, pointman, pointmen, pomander, preadmit, pronated, protamin, ptomaine, radiomen, rationed, reanoint, tamponed, trainmen, triennia

9-letter words

adornment, impainted, imprinted, mediation, nominated, perdition, predation, prenomina, prominent, protamine, rendition

10-letter words

antimodern, antimonide, inordinate, ordainment

11-letter words

aminopterin, predominant

Piet Mondrian is an abstract painter born in Holland; (in Dutch: Mondriaan) He started as young painter in a late Dutch Impressionism style, painting the Dutch flat landscapes around Amsterdam. Reflections in water and his concentration on trees is in these early paintings easily to discover, as well as his favourite oval form. Later he worked out the influences of Luminism in Domburg, along the Dutch coast.

Mondrian got strongly influenced by anthroposophy; it was however in a very individual way how he tried to find the relations with options of his modern art; the horizontal and the vertical became synonym for the male and the female aspect in life.

Mondrian left the Netherlands for Paris in 1912 where Cubism was already articulated; it would influence his search in art enormously, especially Picasso's art. Also the dynamic and modern city Paris had its own impact on the sensitive artist Mondrian, as the modern ball room dance he loved and practiced a lot. Mondrian returned in 1914 to Holland and it was until 1919 when he was returning to Paris for the second time. In these years he intensified his art as a modern painter, partly by an intensive exchange on Néo-Plasticism with his De Stijl comrade Theo van Doesburg, the co-founder of the art movement De Stijl. Around 1924-26 they started to disagree on several important points, and both artists developed their own option radically.

Mondrian left Paris in 1938 for the Nazi' threat; he stayed a few years in London and came to New York in 1941. There he admired as a senior artist the art of the much younger and wild Pollock and Lee Krasner very promising. A typical quote of Mondrian:

- Thus we must carefully distinguish between two kinds of reality, one which has an individual character, and one which has a universal appearance… …It is, however, wrong to think that the non-figurative artist finds impressions and emotions received from the outside useless, and regards it even as necessary to fight against them… …It is equally wrong to think that the non-figurative artist creates through "the pure intention of his mechanical process", that he makes "calculated abstractions" and that he wish to "suppress sentiment not only in himself but in the spectator"… …It is thus clear that he has not become a mechanic, but that the progress of science, of technique, of machinery, of life as a whole, has only made him into a living machine, capable of realizing in a pure manner the essence of art. (1937)

* artist quotations from 'Plastic Art and Pure Plastic Art', Piet Mondrian; as quoted in "Artists on Art - from the 14th - 20th centuries", ed. by Robert Goldwater and Marco Treves; Pantheon Books, 1972, London, p. 428

There is not a real real time but he was deffinatly painting in 1912 because that is when pieter cornelis mondrian moved to paris.

Answer 2:

There are museum pieces by him from 1905.